Need dual-Athlon PC with Windows XP Pro, but these usually take a week to ten days to configure, and 2 more to ship. I need one quick.
Maybe Micro Center, but they're usually pretty expensive. http://www.microcenter.com/at_the_stores/chicago.html
I know you want/need it now but if you can't find it in a store i know http://www.tradingcomputers.com/ has a rush order option. Call and talk to them, you may be able to get a super rush if you pay enough. I here good things about them and will buy my next one from them.