Running a bone stock Moto Backflip:
AppBrain: for those of us with A**T&T they get the last say of apps that our phones see. This site shows all, and with their side loader, you can try the "evil" apps on your phone.
Barcode Scanner: enough said
CraigsNotifica (free)- put in your area, what your looking for. when someone posts it, it notifies you... excellent way to post and respond to an item you have found.
Droid Auctions- ebay app
Garage sale rover : pulls up garage sales, lets you read the ads, puts location pins on map to help direct you to the sale. (free)
Police stream (free): listen to police or emergency scanners from all over (not all areas included)
Handsent SMS in combo with Google talk : paid version can read you the text, do a voice response, more text and MMS options than the stock message service
Feebe Ringtone of Android: free ringtones from songs, sound effects, and others