ok here's what i came up with
and the problems w/ the other builds
do NOT get a 7300 card. they are horrible. get a 6600, 6800 or 7600. they're all better.
2nd one: the cpu and ram are a lot more than you will need for a long time and conroes are only worth the money if you wanna OC them anyways. (go w/ one gig of ram and upgrade later to 2 gigs for 100 more if you want)
also the video card isn't nearly good enough for that build.
ok here's the one i made for you:
i didn't pick out a case for you cuz that's something you should pick out. and also don't just go w/ what i recommend. i don't know EXACTLY what you want in this system...when actually you probably don't either or else you'd already be building it. i'd say just show your neighbor these lists and have him/her tell you what they think.
CPU: AM2 Athlon X2 3800 ($152)
MOBO: ASUS M2N-E Socket AM2 ($93)
PSU: Antec TruepowerII 550W ($80)
RAM: CORSAIR XMS2 512MB 240-Pin DDR2 800 ($62 but get 2 totalling $124)
GPU: eVga 7600Gt KO ($160)
Hard Drive: Western Digital 250Gb Sata 2 ($78)
CD/DVD: Lite-on CD/DVD burner ($33)
all of that totals $720 w/o shipping (to nebraska it would've been $13 more)
again that doesn't include a case, monitor, OS or keyboard/mouse but if you just read reviews on cases you'll do fine if you follow ones w/ good reviews and keyboard/mouse combos the same.
hope that helps. any other ?'s PM me and i'll try and answer asap.