Is it possible to run one or more secondary displays using USB display adapters? Which ones work well with Mountain Lion, Parallels 8, Windows 8 and a MacBook Pro?
If you have an older macbook, you might consider the Matrox DualHead2Go as an alternative. It uses the DisplayPort rather than USB, which is much more responsive. http://www.matrox.com/graphics/en/products/gxm/dh2go/digital_me/ If you have a new Macbook with Thunderbolt, then you should be able to daisy-chain thunderbolt devices together to get multiple external displays.
