If I had a Iphone 4 and my contract is about to be renewed I would leave it, upgrade IOS5 and wait till the Iphone 5 comes out, as most contracts these days are 18months you would be tied into the iphone 4s for about a year when the Iphone 5 comes out.

just a logical view, not a Porkie Apple Nerd view.

the shame Porkie the shame