I found out the hard way that sometimes when you make changes to an email account on the iPhone the settings don't stick. My experience was specifically in changing the Advanced » Authentication setting to NTLM for an Exchange account. The problem, however, may be more widespread than that. The solution was easy:
Make your desired changes to the settings in the mail account. Then go back to the account's main screen, scroll to the top, and move the Account slider to OFF. Go back to the Home screen, then go back to settings and turn the account back ON. Check that your settings have saved. That should do it; I hope this helps a lot of people avoid this pesky iPhone issue.
[robg adds: I haven't experienced this, but then again, I haven't changed my account settings and I don't access an Exchange account.]
Hopefully, in the future Apple may add software support for voice recording, but in the meantime, this hint provides a basic way to record notes via voicemail. Dialing your number on your phone calls AT&T's voicemail, but automatically logs in to hear messages. As far as I know, there's no way to record a message in this mode. However, if you call AT&T's voicemail directly, you can enter your phone number and leave a message for yourself. With visual voicemail these messages won't clutter up your voice mailbox and work great as voice notes.
If you dial *#61#, the iPhone will display call forwarding information in the case of a call not answered (you can look here for more codes, or just google GSM code). The first phone number listed should be AT&T's voicemail number. Create a contact with this number, followed by a ',' (hold * for about 2 seconds), followed by your 10-digit cell number. When you call this contact, you'll hear AT&T's automated response, followed by your iPhone dialing your phone number, and then your voicemail greeting. Record your note and hang up. It may take a minute before you receive the message in your visual voicemail.
Syncing your Mail accounts to your iPhone can burn you if you later tweak those settings on the iPhone. Specifically, if you are using IMAP for your mail, and if the locations of your Sent, Trash or Drafts change, you can end up with apparently missing mail. For example, you set your computer Mail app to file Sent mail into a mailbox on your computer, rather than on the IMAP server. However, on your iPhone, you set your Sent mail to be filed on the IMAP server. (This means you changed the settings to something different than to what was synced up in the first place.) I do this because I generate way too much mail to keep all of it on the server, but I want all of my iPhone sent mail available to my computer (which I then file away), but I don't want to have to CC myself for all mail.
If you are still syncing your Mail account in iTunes, this setting will revert each time you sync. So, if you manually change the location of your Sent mail on your iPhone, it all works -- until the next time you sync. Then your iPhone starts filing the mail in its internal memory. What's worse, if you change the setting back (to leaving Sent mail on the IMAP server), the local iPhone Sent mail folder is no longer accessible -- it just disappears. Never fear, though, it didn't go away, it's just not being shown.
The fix is a simple one. In your iPhone Settings » Mail » your account » Advanced, change the Mailbox Behaviors for each of the problematic mailboxes so that you are filing mail on your iPhone (not on the IMAP server). Now in the iPhone Mail app, you can get to the 'lost' folders. The corresponding IMAP versions of these folders should also be available to your iPhone mail. You can now move your email messages into the correct location (one-at-a-time, ugh). Once you are done, change your folder settings back on your iPhone.
As an aside, I have found the iPhone Settings app to be a bit buggy, so this may be voodoo, but it's worked for me: before changing any folder settings, exit all Mail folders in the iPhone Mail app first (so you are at the topmost view). In iTunes, make sure you disable syncing for that mail account. This will leave the settings on your iPhone intact.
iPhone users who use Gmail may have noticed that they receive a copy of sent mail in their inbox. To fix this problem, turn off Use Recent Mode. To disable Use Recent Mode, go to Settings » Mail » Your Gmail account name » Advanced. There's also an Apple support article that covers this issue.
This is a simple tip but useful. I've come to rely on the sound of the keyboard on the iPhone since there's no tactile response. However, when typing a particularly long message, the sounds can get irritating (both to myself and those around me).
Fortunately, there's a quick way to silence the keyboard without digging in the settings menu: turn the ringer switch off. This not only silences the ringer and message notifications, but also the keyboard.
Its hard to get arbitrary files onto the iPhone. No disk mode, iPhoto scales down big images, and forwarding yourself files and trying to read PDFs or word docs in iPhone's Mail app is a pain.
The freeware Filemark Maker is a small droplet app that aids in encoding data URLs, aka filemarks, which store the actual bytestream of the file inside a bookmark -- meaning you can sync your favorite eBooks or hi-res photos (like subway maps) to your shiny new iPhone and read them in style, even offline. Simply drop a file on Filemark Maker, bookmark the generated link, and then sync it to your phone.
One needs to sync the bookmarks to the phone, as trying to bookmark the filemark links on the phone crashes it.
Don't try images much bigger than about 1500x1500, which can crash Safari on the iPhone.
Huge PDFs of text work fine, but something fancy like the NYC MTA map brings it to crawl (but it works).
The app is written in Perl and compiled into a droplet using Platypus. Source available on the site.
[robg adds: By way of full disclosure, jamiew is one of the Filemark Maker coauthors. However, given that it's a free open-source app, and it seems to work really well, I felt it worth sharing. Note that if you want to store files on your iPhone, you might want to try iPhoneDrive, which lets your iPhone work in a sort of "disk mode" like that of the iPod. I haven't tested the app myself yet.]
I realized that if an iPhoto album is photocasted, it does not appear in iTunes as available to be synced with the iPhone. The solution is really simple: control-click on the album name and pick the Duplicate Album option. The copied album is not photocasted, and it will appear in iTunes so you can sync it.
With every cell phone that I have owned, they have had a way to put your name on it -- either on the boot up screen or on the main screen (such as with Windows Mobile). But the iPhone doesn't have any way for someone to get the device back to you if it's lost or stolen. Sure, they can go through your phone book and call each contact on that list, but then how would you like getting a call from a stranger claiming to have a cell phone that you may or may not know who it belongs to?
The iPhone lets the user chose a .GIF or .JPG file and use it as your wallpaper (the screen you see when you first turn the iPhone on, and when you're making a call). It's easy to do and can help others (like the police) in getting your iPhone back to you safe and sound. Just add your personal info to any 320x480 image you'd like to use, and then set that as your wallpaper. Read on if you'd like more detailed instructions.
[robg adds: This is a good idea; I've edited Plasma Design's iPhone wallpaper collection to include some contact information. It won't help if the phone is stolen, but if an honest person happens to find it, maybe I'll get it back...]
This blog post contains a bookmarklet to force links in Safari on the iPhone to open on new pages. As noted there:
After experiencing and thoroughly enjoying the iPhone for the weekend, I've found that one of my biggest gripes is that there's no "Open in New Tab" command, which makes all the sense in the world since there is no right click anywhere in the OS.
[robg adds: This works nicely, though I wish the iPhone had the concept of background page loading, so you wouldn't navigate off the frontmost page when clicking a link. Alas, that's not the case, but this is still better than losing your starting page each time you click a link. To get it onto your iPhone, add the bookmarklet to Safari's bookmarks on your Mac, then sync the phone. To put it to use, load the page in question, then click the "Open in New Tab" entry on your bookmarks bar. This will add the "open in new page" icon to each link on the page.]