This seems to be the right place to ask, though some of the 2009 info seems a trifle stale.
Many people here seem to be setting up 3x1 landscape displays, and I'm no different. My card at the moment is an Asus EAH5850 Top; this has one each DVI, HDMI, and DisplayPort. I have three monitors all at 1680x1050. It appears that any two can work at once, but the third (while Catalyst Control recognizes it) can't be added to a group.
My cable situation: One DVI, one HDMI, and a non-powered DP to DVI cable. I should mention that, for two monitors, the unpowered DP cable works fine-- I've tried DVI and HDMI as well as DVI and DP. But, three at once is the goal.
Now, many people here have had success with the powered Accell:
http://www.amazon.com/Accell-UltraAV-B087B-002B-DisplayPort-Dual-Link/dp/B002ISVI3U/ref=sr_1_1?ie=UTF8&qid=1291010291&sr=8-1 (US$86.32)
But the ATi and Eyefinity marks are all over some unpowered ones:
http://www.amazon.com/gp/product/B004071ZX0/ref=ord_cart_shr?ie=UTF8&m=ATVPDKIKX0DER (US$29.99)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814999030&cm_re=displayport_to_DVI-_-14-999-030-_-Product (US$26.99)
...and I'd much rather spend $30 than $87. The adapters say they support up to 1920x1200, so my 1680x1050 monitor should be compatible. Right?
My goal is to get a 5040x1050 display. Any help in this direction would be much appreciated.