While this might only help a few...I have a Volvo iPod hookup in my car, and it works with my iPhone, but a screen titled "Accessory Attached" appears. In this mode, I am not able to navigate my iPhone's music. Instead, I am limited to the first 10 playlists on my phone.
Holding the Home button for six seconds releases the iPhone from the car's clutches, and I can now navigate through (while stopped) and play any song I want on my iPhone through my car's speakers.
I hope this trick not only helps other Volvo owners, but possibly others who have devices that are locked up on playback by their accessories.
The system requirements for the iPhone state that it requires a computer with a USB 2.0 port. In actuality, however, I had observed that iTunes would sync with an iPhone on a iMac G4 with only a USB 1.0 port. Hence, I was surprised when iTunes running on a 20" iMac G4 computers could not see the iPhone, but iPhoto could. Because calling Apple Support was not an option (iPhone requires USB 2.0 ports), I attempted to solve the problem myself.
The 20" iMac G4 has three USB 1.0 ports. Surprisingly, the System Profiler indicated that the iPhone was attached to a fourth, phantom USB 2.0 port. This did not seem correct, as other iMac G4 computers showed the iPhone connecting to one of the three physical USB 1.0 ports.
I decided to remove the phantom USB 2.0 port. Be warned that the following procedure, while working on my system, may, if followed, prevent your system from restarting or impair its operation in some horrible manner. If you decide to remove a phantom USB 2.0 port, proceed at your own risk after being sure you have a current backup of your system.
So you had an iPod that would nicely plug into your car. You get the iPhone and because the iPhone's headphone connector is recessed, your cable does not exactly fit. You can't hear the music through your car stereo.
Instead of hacking your $20 Monster cable, buy a couple of cheap parts from Radio Shack and create an adapter for the existing cable in your car. You'll need a 1/8th inch coupler (part number 274-1555) and a 1ft Stereo Audio Cable (part number 42-2497). With a sharp knife, cut about 1/4th inch of one side of the cable's plastic casing at one end. On the other end, plug in (push hard) the coupler and then plug in your car cable to the cable. You are all set.
Now you can remove the special iPhone cable at any time for old iPods, and your iPhone works in your car. No hacking of the nice car cable required.
Safari on the iPhone is pretty happy with Google Docs and Calendar (especially with the slim mobile calendar view that Google automatically sends to the iPhone), but it chokes on Spreadsheets. If you accept the compatibility warning when opening a sheet, it will load it, but not ideally (e.g., it won't scroll to the bottom of long documents).
My solution for viewing Spreadsheets is to load the Preview view of the sheet. This can also be bookmarked for quick access to the most up-to-date version of the sheet. Of course you can't edit that way, but reading works great with zooming, scrolling, etc.
If you are like me and noticed that not all your emails were being sent when you were on a wi-fi network because of SMTP server settings for local networks, or you noticed that emails set to send via AT&T's SMTP server would only send when connected to the EDGE network (or you're paranoid about sending email via AT&T servers), you can use Gmail as your master SMTP server that will work over both Edge and wi-fi.
I noticed this issue when setting up my work email with the iPhone. My work email only uses the local SMTP of our ISP. My immediate solution was to use AT&T's SMTP server cwmx.com. But I noticed that this would only send if I was solely on the EDGE network. So if I were at home and I was connected to my wi-fi, I would have to turn off my wi-fi on the iPhone and get on the EDGE network to respond to a work email. I found this annoying.
My solution was to use Gmail's SMTP server with an account that I have there, and then use Gmail to spoof my return address so that the emails would appear to come from my work address.
Just enter your text via the onscreen keyboard, then click the E-mail button.
You can use iSync instead of iTunes to sync up your iPhone. There's no need to add the iPhone as a device within iSync. It already seems to be there, it's just hidden. Obviously, iTunes controls what is synced, but iSync seems to find changes make to your address book and calendar just fine.
I haven't tested it with transferring of music or video, and I would be surprised if those items synced. To do quick syncs of other data, though, I added iSync to the menu bar and disabled auto-syncing of the iPhone when it is plugged in and launches iTunes. Now there's no delay in waiting for iTunes to launch in order to perform a simple sync of my calendar or address book.
Every iPhone review I've read (and I've read a lot) has stated in no uncertain terms that Bluetooth only works with Apple's hands free headset. But after reading this tutorial, I decided to see what I could find. It turns out that Proximity can find, and lose, my iPhone.
I've only tried triggering a few simple AppleScripts, but it has potential. I've noticed that the iPhone never stops searching for devices (well, the spinner in Bluetooth settings never stops), and this may seriously reduce battery life, but I've gotten inconsistent results at best. Running scripts is nowhere near as useful as a true wireless sync, but it's a step in the right direction.
[robg adds: The linked blog entry contains some pretty useful scripts to run with Proximity.]
I noticed that if i've loaded up Diamenty (a Bejeweled clone; i have mixed feelings about that) and switch into airplane mode, the game still seems to run just fine. I haven't tested this extensively, but I spent five minutes with it in airplane mode, and it seemed to work just fine.
So if you're about to embark on a flight, you might load up a few iPhone games on Safari pages, switch to airplane mode, and see if they continue to work.
Want to quickly scan your appointments for a month in the iPhone's calendar? Touch and hold your finger on a day (in month view), then just drag your finger around the screen. As you move from day to day, the bottom section of the screen will update with that day's events. This is a great way to quickly scan your upcoming activities with just one tap.