To summarize, the internet picture thing is solved.
I simply hook the other cable from my middle monitor into the free output on my graphics card. If I want a true, nonstretched image I can turn on that display. This is fine.
In games, especially Everquest 2 that I've played the most since getting this setup, I cannot tell there is stretching, and the HUGE wideness is immersing and fun!
I would assume that anyone who buys a TH2Go for use on three widescreen monitors would be fully aware of the output capabilites and limitations when viewing on such aspect monitors.
I'd say there are enough people who own stuff (like sailboats, sports cars, Blackberries) who haven't figured out how to use them yet to disprove that theory. So I didn't know the difference between 16:9 and 16:10, the marketing copy didn't indicate there was anything to know. I made the monitor purchasing decision based on Matrox's FAQ:
"Do I need a special brand of monitor?
TripleHead2Go can be hooked up to any monitor, including flat panel monitors. To take full advantage of TripleHead2Go, we recommend you use three identical monitors (that is, monitors that support the same monitor settings such as monitor resolution and refresh rate)."
So I simply went looking for less than 8ms response time, small bezels, and around $200-$250 per monitor.
I tried asking on other forums for suggestions but they were mostly answers from people who didn't own TH2Gos and didn't have anything helpful to say.
Matrox's fault that I have a little inconsequential stretching? No.
The responsibility rests on me, I could have done more research, but they could help people like me who assumed that all there was to monitors was hooking them up by making clearer suggestions in their marketing material.
OK, enough time spent justifying myself. Time to play some more games, I gotta finish Infernal (nice graphics, dumb game).