Just a thought, but
Alarm & Timer need to run so that they can function correctly and "alarm" at the given time.
Amazon App Store (what a name ripoff) needs to check to see if there are any updates to your installed apps
Double Twist needs to check on the availability of a wifi network so that it can "automatically sync"
Skype Mobile needs to be ready for any incoming calls
Verizon Navigator needs to know exactly where it is at any given time
Just a thought