In short, they’re in Android, not the iPhone.
This is a common frustration to iPhone application developers and product visionaries. You can’t run applications in the background. Think of all the features un-implemented due to this colossal disclusion.
Granted, there’s a reason Apple chose to omit this from their SDK. Lucky for me and you, Android chose to pay special attention to it. What we would call “daemons” on a standard operating system, Android refers to as “Services”.
Now we can do a cadre of interesting things, like wait for communication from a server while we check our email or play a game of Sudoku. Even better, we can bind other activities to these services to let us know when threads complete or to communicate with them directly from another app!
That makes for one happy droid!