Just thought i'd mention that I've had the iphone 4 for a few weeks now, and like everyone else I know who's actually got one, have had no problems whatsoever with signal. I really feel like this whole thing was blown massively out of all proportion by a media who wanted Apple to slip up for once.
The only thing that does slightly annoy me is that the glass back is so smooth, that is gradually slides off any surface that isn't 100% horizontal, so you often hear a'clunk' a few minutes after you put it down. Fortunately it's robust enough to deal with any small fall without scratching, but the rounded back of it's predecessors certainly seemed to have a bit more grip.
The only thing that does slightly annoy me is that the glass back is so smooth, that is gradually slides off any surface that isn't 100% horizontal, so you often hear a'clunk' a few minutes after you put it down. Fortunately it's robust enough to deal with any small fall without scratching, but the rounded back of it's predecessors certainly seemed to have a bit more grip.