Two things at once

I suppose I should actually read the manual sometime. It’s taken me until now to discover that you can still talk on the phone and use applications by switching to speaker ( or using the earpiece ) and then pressing the home button.

So now when someone gives me information I need to write down, I can just open the notepad while I talk.

I think this is the reason why Apple does not allow third-party applications to run in the background. They want to ensure that this useful feature is not compromised.