if you like to make music and sounds:
technoBox - amazing 808/909 drum machine
technoBox: Your mobile techno studio for iPhone / iPod touch
PASY02 -
Pankaku iPhone Applications » PASY02
Looptastic -
Looptastic Electro Edition for iPhone Review | iPhone Alley
NLogSynth - incredibly realistic analog synth simulator...sound through speakers is amazing.
Tempo Rubato
DrumMeister - very fun drum maching and sounds great.
Drum Meister
PakISound1-
PaklSound1 Home
Audio Palette -
audio palette
otherwise:
ILikeConcerts is great. It will tell you who is playing where, and when. Picks up smaller venues too. This is one of my favorites.
Local Concerts App on iPhone - iLike
New York Times
BBC Reader
Pandora
Drinks - gives drink recipes
Guitar Chords
TyroTuner - instrument tuner
Wikipanion
Urban Spoon
UseYourHandwriting - to do list using your hand writing
Pac Man lite
Photo Shop Mobile