ConvertIt - A great little app that can be used to convert images to multiple image formats really quickly. Just drag and drop on the icon. I’m running it as a menu bar app only but it can be configured to run in the Dock as well.
Delibar - App to manage all my Pinboard bookmarks. Also an iPhone app
Dropbox - Just to make sure everything is in sync
TextExpander - While I don’t use it to its fullest extent, it is great for typing long repetitive strings in the Terminal
Location - Just the Mac OS X Lion icon letting me know what apps are currently using my Mac’s location data.
Sidekick (Previously NetworkLocation) - I use this to automate my Mac depending on where it is. For example when I get into work it will drop my volume, mount the work server drive and open up Remote Desktop Connection. I used to use AirPortLocation but since the dev isn’t supporting Lion I’ve had to switch. I only hope the devs of Sidekick add more features in the future.
CloudApp - Used on almost a hourly basis to upload pictures, links, etc. for easy sharing.
unDock - Great for cleanly ejecting all manner of drives be they network, Time Machine or USB/FW ones. Allows you to run scripts as well.
Seamless - Transitions songs from iPhone to Mac and back again.
Hazel - There isn’t enough room here to say all the good things that I want to about Hazel. If you don’t have it, get it. Think Folder Actions on steroids that have been given Green Lantern’s ring, is Superman’s secret brother, & has been soaked in cosmic rays.
Time Machine - Just to monitor how everything is running.
Wi-Fi - Because I’m constantly having to change networks.
iStat Menus 3 - This app is great. It lets me monitor what my Mac is doing at a glance and if I need more information I simply click on one of the stats to bring up a full menu. I’ve got it monitoring my Disk Activity, Network, Disk Usage, Memory, CPU, Battery, & Date and Time.
(From James Smith)