I was not expecting so many of you to use task killers. Considering since Froyo they are
absolutely worthless.
Anyway, mah list.
First off, root and rom your phone. (CM9 is coming out soon, yay!)
One time use utilities (a lot of these come with cm7)
AdFree - get rid of ads
Adobe Reader - pdf
BatteryCalibrator - recalibrate your battery: To get maximum life use in combination with a tool called Current Widget
Rom manager - to manage your roms
Spare Parts Plus - to manage your system
OS Monitor - to monitor cpu usage and the like
Apps
3G watchdog - keep track of data usage
Anti Droid Theft - keep track of your phone
Barcode Scanner - read qr codes
Calculus Tools - I'm a math geek
Dolphin Browser HD - Must have browser
Gas Buddy - App isn't very good, but when it is, you get the cheapest gas in town!
Game Dev Story - fun little game
Google Goggles - App isn't very good, but sometimes fun to Google stuff with
Hacker's Keyboard - BEST keyboard
Handcent SMS - BEST text messaging app (I've used them all, trust me)
Hybrid Stopwatch - very good timer
MX Video Player - watch /any/ video file format on your phone
Note Everything - note some stuff
Terminal Emulator - cause everyone is a leet hacker
Urban Spoon - find good foods around you
Widget Locker - customize your lock screen
Words Free - scrabble game
The ones in bold I probably couldn't live without
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