... I do not really know, where to post this ... so I put it here ...

I today tested this little and not really expensive toy that lets you extend a single graphics card output with 2048x767 to two outputs with 1024x768 each (or 2560x1024 --> 2x 1280x1024).
Diffent to what Matrox says, this box seems to work without problems with every graphics card that is able to output the resolutions 2048x768 or 2560x1024.
The only restriction is, that with 2048x768 only refresh rates of 60,75 and 85Hz and for 2560x1024 only 60Hz are working (to bad for video that 50Hz is not working).
The Image quality looks amazingly good to me.

I think this is a nice and interesting little toy to make a "3 or even 4 head graphics-card" (4 head not tested) out of a normal DualHead graphics card with all the 3d and shader capabilities of the current nvidia or ati cards.
http://www.matrox.com/graphics/offhome/dh2go/home.cfmhttp://www.matrox.com/graphics/offhome/dh2go/DualHead2Go_datasheet.pdfhttp://www.trustedreviews.com/article.aspx?page=4957&head=18

MSBERGER