Spend your money however you want, but personally I think buying a computer with it would be a bad choice. You could invest it, you could save it up in the bank, collect some interest and buy maybe a car, who knows. Whatever, the choice is yours.
But if you are going to get a computer, I wouldn't get a Dell (although that is a really nice computer). I've heard good things about
www.abspc.com . You choose the parts of your PC on their site, and then they put it together and ship it. But I will tell you that I had a shitty experience with a similar site, ibuypower.com. If you follow my advice, make sure you get a good waruntee (actually, that should go for any computer you get that is that expensive). And also, do you research before you make that big a purchase. There are plenty of techy forums out there with people who can help immensely (I've seen it).