for those wondering how to close apps, if there is no close button
double tap the home button, you then get a list at the bottom
hold one of the apps, and a - will appear, press the - and it will close (there will probably be loads, until they catch up on the fact home won't close them and update their apps)
and for those of you who want to itunes on multiple computers, mine wouldnt work earlier, after i upgraded (it wanted to wipe the phone) until i found this. which probably works if you want to use it on more than one computer (let's face it who doesnt have this now).
How to sync an iPhone with two (or more) Computers :: Shiny Things