If you have Twitter handles for your friends and colleagues in your Contacts, you can easily view tweets those people have made. Just open a card in Contacts, click on Twitter, then choose View Tweets. If you have the official Twitter app installed, it will open displaying tweets from that person. If not, a web page will open on the Twitter web site.
You can also tweet to someone from OS X by clicking on Twitter, and choosing Tweet, as long as you have set up your Twitter account in the Mail, Contacts & Calendars pane of System Preferences.
While viewing tweets is nice, it would be even better if they could open in one's favorite Twitter client. But that would presumably involve hacking Contacts. Anyone interested in trying to figure it out?
You can add certain types of files as attachments to Notes by dragging and dropping them. They'll sync via iCloud, so this can be an easy way to share files across two Macs. You can also access attachments you've added to notes from the icloud.com website; to download an attachment in a note, just double-click it.
[kirkmc adds: You cannot, however, access file attachments on iOS devices; they just show up as paper clips. Surprisingly, even photos don't show up in notes on my iPhone. Note syncing is abysmal, as is much of iCloud syncing; notes don't update correctly, or at all, some notes can't be saved from the web interface, and on iOS, it's a crap shoot whether notes display or not.]
I'm not sure when this became available, but I don't seem to remember it happening before 10.8. You can now take screenshots of sheets within a window by pressing Command-Shift-4.
A sheet is a dialog that drops down from a window, but is attached to that window. To take a screen shot of one, press Command-Shift-4, then press the space bar, which displays a small camera cursor that you use to select the window to shoot. If you want to take a screenshot of a sheet, press the Command key, and you can select only that sheet, and not the entire window behind it.
You can try this by going to the Finder and pressing Command-Shift-G, or choosing Go > Go to Folder; what displays is a sheet.
[kirkmc adds: I certainly didn't know this, and don't find it anywhere on the site.]
This is less of a hint than a heads up. I was chatting with Rob Griffiths yesterday, the creator of this web site, wondering if one can partition a Fusion drive. It turns out that you can, but only the hard drive part of it. This, and many other questions, are addressed in this Apple technical note, which is worth reading. The Fusion drive is a new technology, and has certain limitations because of the way it works, but it can be useful to see what these limitations are.
"This update uninstalls the Apple-provided Java applet plug-in from all web browsers. To use applets on a web page, click on the region labeled "Missing plug-in" to go download the latest version of the Java applet plug-in from Oracle."
If you wish to re-enable the original Java applet plug-in - which is not uninstalled, as claimed above, but simply disabled - Apple has published a technical note explaining how to do this. There are a few Terminal commands, including creating a couple of symlinks. The technical note also explains how to disable Java Web Start.
The technical note also gives a URL where you can download the Oracle Java 7 JRE, which will be the future version of Java for OS X.
Having searched the web, I could not find any reference to playing 1080p videos on the 2nd generation Apple TV (fully updated with the latest firmware). The Wikipedia entry, for example, states that it is 720p only. But my experiments show that 1080p movies can play just fine. The problem comes when downloading 1080p movies from the iTunes store. This hint shows how to quickly play such downloads.
Prior to purchasing a 1080p movie from the iTunes store I ran many experiments with self-created videos (Blu-Ray rips) to ensure that such HD files could be played.
So I completed my experiments by purchasing a 1080p movie (Vertigo to be exact). iTunes downloads two versions when making such purchases: the HD version and a SD one. Both are stored in the same iTunes folder and iTunes itself shows an HD:SD badge. The problem here is that the 2nd generation Apple TV only shows the SD version and therefore only plays the SD version.
To play the HD version, locate the files in the Finder, then delete the movie from iTunes, opting to keep the files. Then add back just the HD version and the 2nd generation Apple TV shows it as HD and plays as HD. There was a very small pause at the start of the film as I was watching, but I have a fast network, so the download to the Apple TV was soon a few minutes ahead of the play position.
I think I will actually go back to purchasing the 720p versions as my eyes are not quite what they were and I cannot really tell the difference. This was just an experiment to prove a point.
[kirkmc adds: I don't have a 2nd generation Apple TV to test this…
Update: It turns out that the Apple TV 2 can only output 720p, so it must be downscaling the 1080p videos. However, according to the poster, it is playing these videos, so you can have only 1080p videos in your iTunes library and play them through this device, apparently, instead of it defaulting to SD versions. But I still can't test this to see what's really going on.]
You can add tags to iCloud e-mail addresses, to be able to sort messages with Mail rules, for example. To do this, use an address with your name, a plus sign (+), then a tag. For example: firstname.lastname@example.org. This also works with mac.com and me.com addresses.
With these tags, you can set up rules in Mail or another e-mail client to sort or redirect messages as desired.
You can now share lists of reminders from the iCloud web site (not individual reminders, however). To do this, hover your cursor over on a list in the left-hand column of the Reminders interface, then click in the little round sharing icon that displays at the right of the list's name. Enter an e-mail address for the person you want to share the list with, then click Done. You can add several people if you wish. Any of the users of these shared lists can add or delete reminders, or mark them as completed.
If you use top in Terminal, you may occasionally see apps with hugeVSIZE values. I know this because Witch, one of our apps, is an example of such—it's VSIZE can exceed 11GB.
In trying to figure out why this was so (short answer seems to be: we can't control it, but it's not a problem), I ran across an interesting command, vmmap. This command will spew out a ton of detail about virtual memory usage. Stringing a couple Unix commands together, though, you can extract just the summary portion of the report.