Free things that ought to be on your Mac

GmailStatus - Puts a little unread messge count on your menu bar and can play a new mail sound when new messages show up. Gets rid of an entire Safari window that performed the same function for me. Sweet!

SizzlingKeys - Systemwide global hotkeys for iTunes. Opt-Command-Space now pauses and unpauses iTunes regardless of what app has the focus. It also has a little floating window that displays the song title when a new song starts. For the life of me, I don't understand why iTunes does't support a global pause key right out of the box. Indispensable.

WeatherDock - Fetches weather conditions from and displays it in a dock icon. You can click it to see the five day forecast. Also has the coolguy feature where you can set home/work locations. So mine shows Menlo Park from 7 to 4 Mon-Fri and San Jose the rest of the time.