Tom, using NewEgg I came up with a somewhat different parts list. Unlike ZipZoomFly, NewEgg doesn't have free shipping on everything so the total is without shipping. I'm just posting the component and the part no. so you can search it out and look for yourself.
http://www.newegg.com/
LG 18X DVD±RW
N82E16827136108
ASRock 6100/430 Socket AM2 motherboard
N82E16813157101
eVGA 7600GT 256MB video card
N82E16814130073
Antec SmartPower 2.0 500W power supply
N82E16817103937
Corsair ValueRAM 2GB kit
N82E16820145098
AMD Athlon 64 X2 3600+
N82E16819103046
Windows XP Pro SP2b
N82E16832116175
The total NewEgg shows is $654.94. There's about $50 in rebates not deducted from the total and probably about $20 more to add in shipping. I don't screw around with rebates personally. Oooh wait a minute NewEgg has a distribution center in NJ so you'd have to pay taxes. I'd stick with ZipZoomFly.
OK so ZZF... I changed the parts list some because there were some features you may want that were missing on the first motherboard. The new configuration has 2GB RAM and a slightly less powerful video card.
http://www.zipzoomfly.com/
LG 18X DVD±RW
174262
AMD Athlon64 X2 3800+
80721-10
Corsair 2GB kit
85016-47
ASUS M2N AMD Socket AM2 motherboard
247112
Antec SmartPower 2.0 500W power supply
273503
eVGA 7600GT 256MB video card
322834
Microsoft Windows XP Pro SP2b
604631
Total: $679.46 including shipping and there is no tax.