[kraegar]

Things I use constantly:

Google Voice (if you're already a GV user, it's perfect, if not, it's worth checking out)
Google voice locations (GPS way to switch which #'s your google voice # rings to)
Locale - $10, but awesome. Lets you program conditions (location, wifi network availability, phone orientation, etc) and things to do when that condition is met (change the wallpaper, ringtone, volume, speakerphone, google voice settings... there's a ton of plugins for it)
Barcode Scanner - Reads in barcodes (Doesn't process them)
Shopper or ShopSavvy - Scan a barcode, compare prices for it online and nearby
Pandora or Stitcher- Streaming radio
Facebook & Twitter.
Sportstap - Sporting news & info
Gamefly Gamecenter (Awesome if you have a gamefly sub)
Evernote - online note taking, create notes on your phone, instantly have them online (for your PC etc)
Dropbox - Filesharing between PCs & phone, awesome.
Mint.com - Budgeting
Nesoid - Nintendo emulator, works perfectly
photoshop.com - photo editing, works great
unit converter
Beautiful Widgets - Nice clock, nice looking widgets
DxTop - Homescreen replacement, gives you 5 homescreens as well.

I have lots more that I have & think are good, but that's a decent start :)

Tony