These are just a few things that I have from Cydia on my iPhone 4 that make it more useful:
1) LockInfo
2) Grid Lock
3) Clear Lockscreen 4.0
4) Clear Call
5) Pull to refresh safari
6) Fullscreen for safari
7) Haptic Pro
8) iFile
9) SBSettings
10) Shrink
11) MyWi 4.0
12) Fake Carrier
Sent from my iPhone 4 using Tapatalk.