I just made one with two slot-brackets and a spare 90mm fan. Works perfectly, allowed me to get at least 10 more mhz out of GF3 Ti200, up on 240/530 now.
Didn't test it further as I noticed that I had unseated one of my ram modules because it only said 512mb ram, put it back in so I had 1024 again and now I can't even oc my gfx-card to 230 core anymore

I'm going to try and find a solution to this problem, as I both want 1Gb ram AND a much oc'ed graphics card, if you have any ideas please post 'em.