Power concerns

So I'm putting my new pc together as we speak. And I'm concerned with my power supply's headroom for future improvements. Currently I'm running an Antec NeoHe 500watt power supply. Now seeing as how I'm currently running an e6600, 3 hd's (raptor and 2 barracudas in raid 0), and an 8600gt it runs just fine. But I plan on using the step up program in two months to go to a 8800 GTX. If I keep the same power supply will my comp take a nosedive? I'm not willing to fry 1k+ in computer parts because of the supply. The recommendation for the GTX is 470, but does that mean it's max use on it's own is 470? 30 watts to run the rest of my s ystem seems less than promising.

So tossing on a GTX won't cause a meltdown?

It's okay, I've got a antec 900 case. If it won't stay cool then I won't be a ble to get by with anything haha.

You should not have anything to worry about. Here's an approximate breakdown of your max power consumption on the 12v rails:

E6600 @ 3.0GHz.......................................70w
8800GTX..................................................140w
Raptor HDD...............................................30w
2 7200RPM HDD........................................24w
1 DVD Drive...............................................12w
2 120mm Case Fans..................................12w
1 Typical CPU Fan.......................................5w

Total Power Consumption on 12v Rails.......293w

Total Amp Consumption on 12v Rails.........24.4a