Bought one of these Winstar USB graphics adapters:

http://www.amazon.co.uk/gp/product/B0037...ASIN=B0037ZCEFO

It is much smaller than I expected. The hardware, packaging, manual etc are totally generic (but oddly high quality). There isn't a single mention of Winstar or indeed any other company on it. The back of the manual shows images of a 8 other DisplayLink products that are supposedly produced by a series of different companies. I suspect in actuality that they are all made for/by DisplayLink themselves.

It ships with a DVI-VGA adapter and a funky DVI-HDMI adapter with a joint in it that rotates 180 degrees (which would be handy if you were trying to cram it in behind a TV somewhere).

I didn't bother using the driver CD supplied, Windows 7 downloaded some drivers for me.

It works well. I had expected it to use up noticable CPU time, but it doesn't seem to.

Windows are probably a tiny bit laggy when dragging them around, but that could easily just be my imagination.

It copes happily with typical in browser video on Vimeo and Youtube. It copes happily with 360p video in VLC either windowed or full screen.

I copes ok with 720p torrents in VLC at 1:1. It starts to struggle with 720p zoomed to full screen, but then do does my laptop video when it is running on the internal GPU.

I think when it is playing 720p it starts dropping frames, but does so very smoothly (that might well also be my imagination as well).

All this was on my Core 2 Duo 2.2GHz laptop with 6GB of RAM running Windows 7. Will try it on OSX later.

All in all, very pleased with it. If I didn't know it, I wouldn't realise I wasn't still running off the docking station video card.