How can I make my multi-monitor setup wrap around?

I have a 4-monitor setup on Win7 Ultimate (nVidia 8800GTS + 6600GT), and I'm experimenting with various layouts for optimal awesomeness.

One thing that really bugs me is the sheer distance that the mouse pointer needs to travel horizontally to get from the left edge of the left screen to the right edge of the right screen. It would be tremendously awesome if I could set it up to wrap around so that if I move the cursor all the way left it wraps around to the right again. Unfortunately, I can't for the life of me find any way to make this happen.

Googling around gives a Mac utility that does exactly what I want; someone also suggested connecting the computer to itself with Synergy, which seems awfully kludgey and I never got it working anyway. Is this possible with Windows? I'm happy to get my hands dirty with some COM scripting if necessary, but I don't really know the Windows API...

The closest i was able to find with a quick search was this. it doesn't wrap but instead uses keyboard shortcuts to let you jump the mouse cursor to a different monitor.

If you tell Windows that your monitors are in a 2x2 configuration rather than a 4x1 (ie tell it that two are above the other two) then you can move quickly to the further screens by moving the mouse off the top or bottom of the screen.

This does assume that you don't use apps that span across multiple screens, if generally keep your apps to one screen each (or remember how they're paired to span across two) then this could work quite neatly.