One of my biggest bugbears with Eyefinity is the inability to switch easily between multiple desktops and the giant Eyefinity desktop...
I bought my 3x 2209WAs to use a landscape multiple desktop solution whilst studying my MS certification (one display for 2003/2008 Server, one for XP/Vista/W7, one for e-book/web/onenote), for honing my Java skills and having a whopping display area for playing HL2/Crysis/any other app I can get working
Unfortunately ATi's drivers aren't suitable for easy switching between multiple desktops and an Eyefinity setup and require some man-handling to switch between the two modes. Application support is extremely hit and miss, with some apps supporting it fully, some having small bugs, and some being completely unusable. Perhaps the worst failure is when Eyefinity fails in it's capacity completely and the same display is replicated across all 3 monitors. It is truly immersive when it works, and although the end monitors distort the image it's generally not noticeable, especially on the periphery of your vision.
Just need to get used to looking left and right to find my Start button and my system tray icons now!