I was originally skeptical of Apple’s multi-tasking implementation in iOS4. The fact that apps were limited in their ability to stay alive was frustrating, except that there’s an option that allows devs to complete the last operation before the OS shuts it down.
Bylines, the RSS reader, will finish a sync. Now, even on Edge only, I can hit the refresh button then go do something else and let it finish it’s sync.
One of the most frustrating and battery killing things about iPhone OS < 4 was that I had to stare at my RSS reader/twitter client/web browser app while it was refreshing it's content. Since I want that sort of refresh to be as fast as possible, I always used 3G to do it, which crushes batteries. Now that I have the option to do that in the background, I can let the phone do it over a leisurely, battery-sipping Edge connection. Bravo, Apple. Bravo.