The nub works surprisingly well. It's too bad there aren't two of them but I doubt there is any chance of PSP v1 ever supporting a second nub. The only annoyance is that the num can get bit tricky to control properly when it gets sweaty.

On the topic of the PSP as a whole. I really wonder what Sony is up to. Are they clueless or working on something top secret. The iPhone is stomping all over the mobile market and might even impact on mobile gaming too. I hope for Sony's sake they are not sitting around twiddling their thumbs and have a PSP2 / phone thing ready to launch by this time next year at the latest.