Well, since xmas is nearly coming, i was thinking of jumping on the bandwagon and maybe asking for a nintendo ds lite, but then im not sure the difference between that and the psp, which is better, i would probably use it for games, at the moment i just use my pc mainly for sim and tycoon games, any advice????

I don't have a DS so can only go by what I have seen and tried in the stores, and whilst the PSP wins hands down on specification, Nintendo always come up trumps on imaginitive and involving gameplay.
and wouldn't swap it for a DS as the games I like to play tend to be the ones that the PSP's superior graphics are more suited to. However If it was me in the OP's situation and I was limited to one then I would try and get some time with both consoles and try them both with a couple of different games and then make my decision based on some practical experience