3rd Party Background Apps / Cydia / Hourly Chime

[greylock]

I have read in a number of places that Apple does not allow third party apps to run in the background. I am assuming this means that you also cannot add cron type jobs / scheduled tasks that trigger an action at a particular time ? In particular, I would like to obtain (or write) an app that chimes the hours, even when it is not running in the foreground. (This can almost be done with the iphone clock, by setting multiple alarms, however the alarm repeats until the user responds to it, and this is not the behavior I want). Hourly chime apps are pretty common for blackberry and pocketpc, but not the iphone, and I am deducing that this is probably because the iphone does not allow third party apps to run in the background. So questions/comments I had were:

1) Is there an app out there I just don't know about ?
2) In theory, could an app developed for Cydia or Installer on a jailbroken phone have this functionality ?
3) If so, can anyone give a general outline for how to do this, or just where I might look for tips/info on developing code in this environment ?

[greylock]

Okay, just to follow up on this thread. I got some great help over in the irc room. Using Backgrounder app and commercial timer app "RoundTimer" I have what I was looking for. RoundTimer (Round as in a round of boxing) plays a sound once every X minutes or seconds. Using the backgrounder app, major kudos to the author, it can be set to work in the background. Drain on the iphone battery is not bad at all, as iphone is still able to shut off screen and go into lock mode. :cool::cool::cool:

[greylock]

Well, it almost works. Seems that a while after being locked the phone goes into some kind of sleep state, and then the alarm doesn't sound until you unlock it. It's like the timer app hits a barrier when it tries to sound the alarm and doesn't resume until the phone is unlocked. At least I think this is what's happening. Anyone have any explanation/clarification/solution ?