BetterTouchTool - A great way to use all the features of your Magic Mouse or Magic Trackpad.
Windows 7 Notification area - Part of Parallels 6.
Parallels 6 - Runs Windows 7 in a virtual machine.
Alarm Clock Pro - Event scheduler; ftps data every 10 minutes, and mutes and unmutes my system at night and in the morning.
Zooom/2 - Allows for resizing of windows such that they snap to the edges of other windows.
TextExpander - Great way to turn short abbreviations into full text while typing.
Eye-Fi - Uploads pictures from my digital camera wirelessly over Wi-Fi.
Overflow - Application launcher/selector at the press of a button or hot key.
Divvy - Move windows to predefined places on the screen.
Ping Pong - Keeps my ISP honest by pinging a web site every minute to make sure I have connectivity.
Amnesty - Allows widgets to go on the desktop.
MenuEverywhere - Places the menubar for applications at the top of each window.
HoudahSpot - Great front-end to Spotlight.
TinyCal - Shows a calendar on the screen, with GoogleCal appointments.
- Notifications.
CapSee - Indicates on the screen when the caps lock key is pressed.
LogMeIn - Allows my to connect to my computer remotely.
AppleScript - Easily run and edit scripts.
Time Machine - Back ups.
Bluetooth - So I can see how long my mouse battery is.
Eject button - To eject media.
Volume - Changes sound volume.
Spotlight - Self-explanatory.
(From Mike D)