Anyone connected HDMI cables to this box: Matrox TripleHead2Go ? And if yes what adapter did you use?
It depends on which model of the TripleHead2Go you get. If you get the "Digital Edition" (Part: T2G-D3D-IF), then you need a 3rd party DVI->HDMI adapter.
You can get these types of adapters, and cables from places like NewEgg or StarTech.
Here's a link to a 6' cable from StartTech for reference.
If you are using the TripleHead2Go DP (DisplayPort) Edition (Part: T2G-DP-MIF), you'll need a 3rd-party DP->HDMI converter.
Here's one from StarTech for reference.
Edit (more info):
DVI and HDMI are electrically compatible, so a properly wired cable/adapter shouldn't (be able to) cause any problems. I use multiple DVI->HDMI (passive) cables to drive my TV and monitors, and they work perfectly fine.
I haven't used a TripleHead2Go DP version, but as long as it's "Dual-Mode" DisplayPort (AKA "DP++", which it probably is) then a passive adapter to convert to (single-link) HDMI/DVI or Analog is easy, as DP++ had lines in it to specifically allow this.
If it's Just DP (no "++") then you'd need an active (powered) adapter that can pump up the DP signal strength to support HDMI or DVI. See here.
Personally, if I want HDMI, and don't have any DP displays, I'd get the "Digital Edition" and go DVI->HDMI using passive adapters.