SLI Compatible Cards?

[AmatorySquid]

Can someone please tell me a card thats SLI compatible with this one? Thanks! http://www.newegg.com/Product/Product.aspx?Item=N82E16814125506

 

[Gam3r01]

Any other 680.

 

[bignastyid]

Any other 4Gb 680 should work.