I took the MSI fans off of the shroud / heatsink and zip tied 2 x $5 80mm case fans (4000 RPM, 52cfm) (http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=8208357&CatId=494) (tigerdirect . ca model# FD08025B1H3/4)

The MSI 7950 I have is hashing 670 Kh/s, 1125 engine clock, 1500 memory clock, voltage 1088, @ 71C with this setup (approximately a week).

The fans on my sapphire cards are starting to go - I believe I'll do the same with them (but probably look for 90mm fans for them as the opening on the shroud is larger).