I have an ap called Sys that shows me what is running. The 3g does not do the multi-tasking available on the newer iPhone. The process shows mail, phone, sys(the ap itself) and sometimes App manager. Then there is a list of processes similar to a basic UNIX system which I would expect. I would have to know to look for a specific one to know what should or should not be running.

Regarding the OS: The older phones can't up date to the latest OS.