Going by the Passmark chart  LINK the GTX580 is the winner in both performance and cost.  That should light your afterburners.

if only I could afford to replace my 8800GT with one. 

http://www.asus.com.au/Graphics_Cards/NVIDIA_Series/ENGTX5802DI1536MD5/#specifications 

That one's available where I get my 'bits'...

Well my opinion is if you can afford the extra I would go with the 590 due to the fact that it'll handle features better in the future and would lengthen the time which you would need to upgrade again.

Jafo i believe in you and i know you will make the right choice- but for heaven sakes don't hurt me in the process because i can't afford the gtx590 and ill be very jalous if you purchased this card.

Im rich but i aint that rich so don't buy the 590 just to piss me off? I know we have had our mis-understandings in the past but i can assure you i don't deserve to be stabbed in the back as a result of you buying this card! It aint right Jafo.. Not at all.

Over $700 per card is not something anyone will call a product. Its a collectors item. The glory of playing battlefield 3 with such a beast would put anyone else to shame who hasn't got the card. If you value our mediocre friendship then you will just settle for the 580-ok buddy?

this might help... i would also say the 590GTX but make sure not to get a reference model ( why ?) because they are loud - really loud !
This is just a compare about the 2 cards reference models i assume
http://www.hwcompare.com/9825/geforce-gtx-580-vs-geforce-gtx-590/
keep in mind that that there is already a big brother of the 590 out the "GTX595" im unsure but i know about two models ASUS and EVGA

Well....WEI gets 7.9 and 7.9 in the graphics.....as you'd hope, I guess....

As long as you're airborne, why don't you drop your old card over my place. Please use a chute rather than a missle for delivery though. The neighbors may complain. 

You can find coordinates on GoogleEarth.

I wouldn't, A newer graphics card would handle graphics/video rendering so much better. i7 920 D0 is already overclockable and I've seen some specs at 4.x Ghz. It's more than enough, despite the extreme chips having 6 physical cores It's debatable whether the "extreme" is worth the heavy price tag.

Thanks for that, Web ...interesting insight into the card....

I thought you'd appreciate that.

The default screen cap proggy that comes with the card always seemed to conflict with the game key settings...so used Fraps instead...since it was loaded anyway.

Here's 'me' coming into turn 3 at Albert Park [Melbourne] [worked that corner in '97] .... and yes, I'm not on raceline....anyone where I am has clearly got a problem [me - I was screen-capping].

120fps at full detail .... it's mesmerising watching the shadows and reflections just on the helmet...