Adium has to be one of the best IM applications for the Mac. Adium, first off is free and open-source, and also interfaces with AIM, MSN/Live Messenger, Yahoo Messenger, GTalk/XMPP/Jabber, ICQ, MobileMe, Bonjour, MySpace Talk, Live Journal Talk, Facebook Chat, Lotus Sametime, Novell Groupwise, QQ, and Gadu-Gadu. The interface is very Mac and is fully AppleScritable. Get it for free at AdiumX.com.
For the long-time geeks, you realize that the zip compression format is far from the best: and this utility which can decompress most of any files, also is able to squeeze my 15GB Windows 7 Virtual Machine install into 1.9GB. This utility is a user-interface for the 7z compression engine, and is much easier to install than any command-line utility. Get it for free here.
Readers, if this relevant to you, take a look at WordPress 2.7, I had been using 2.4 for the past 8 months and finally decided to upgrade. It was definitely worth the little effort. All you have to do is disable all of your plug-ins, back-up your database (for good measure) upload all of the files except the wp-contents folder, next upload the *.php file located in the new wp-contents folder to replace the old one. Next login to WordPress and click upgrade. It took about 10 minutes all said and done!