Although I've already done so on my iPhones, I think something that automatically deletes unneeded files, language packs, and launch daemons (user selected w/ job description?). Upon startup, ask a few questions about usage, ex: Ip model, FW (May not be compatible, but LPs are still removable), whether it's used as a phone (Automatically filter out Launch Daemons pertaining to phone usage) ect. Oh, and a choice of compacting files for quicker launches and more HD space would be legit.

Anyway, I'm barely expecting this to be created, just thought it would be among the top downloaded/most usefull apps if created(: Especially for the painstakingly slow iPhone 2g... That's my 2 cents!