Can I connect more than one external monitor to the late 2010 MacBook Air?
Sidecar is a nice product for windows and they have a Mac version, but seems outdated (and in fact I found the Mac version via Google, not through their product page). You might want to contact them in case they have something not shown there.

In any case, the graphic card (and CPU power) in the MBAir will have a “hard” time driving “two large monitors”. 

If you still want to try, this guy over here is using not two, but three displays (plus the macbook’s display) for a total of four. He has a Macbook Pro tho.

He basically tried the Matrox solution and didn’t like it for various reasons he outlines in the post, so he tried the Diamond BVU195 USB-DVI adapter (he brought two).

Go ahead and read his post, he posts his impressions, problems and even links where to buy the things and their prices. You will surely need a couple of USB Hubs for that.

UPDATE: New products are now available for Mac as Matrox Introduces New Mac-Friendly DualHead2Go DP and TripleHead2Go DP Multi-Monitor Adapters.