There's one point Glenn forgot to mention: GIF files support multiple "frames," which means they can be used for simple animation. I believe this feature is exclusive to GIF since, until Netscape supported it, no one had bothered with this rather obscure part of the GIF specification. PNG was designed before Netscape supported multi-frame GIFs, and the designers didn't see the point of supporting this completely unused feature. Pity.
Avoid Simple Typos
If, like me, you find yourself typing 2911 in place of 2011 entirely too often, you can have Mac OS X (either Lion or Snow Leopard) fix such typos for you automatically. Just open the Language & Text pane of System Preferences, click the Text button at the top, and then add a text substitution by clicking the + button underneath the list. It won't work everywhere (for that you'll want a utility like Smile's TextExpander), but it should work in applications like Pages and TextEdit, and in Save dialog boxes.
Put your company and products in front of tens of thousands of
savvy, committed Apple users who actually buy stuff.
More information: <http://tidbits.com/advertising.html>