I got to thinking about having a pet gecko when I noticed something, geckos in fallout classics are bipedal. Though in one of the first screenshots of the Courier throwing a grenade at geckos, ones of them was on four legs. A gecko in the G4TV vid with MCA was biped in New Vegas too.

So are they both?

Eh?
They got arms?
By the way, http://www.youtube.com/watch?v=MexyuH-m97A

I would say both. There's different gecko types in the game. I guess they distinguish themselves from the others.

when running it seems as they run on four legs.

some lizards when they attack they can run on two legs , to make them selfs look bigger so im guessing it sort of the same in fallout

I would like it if the geckoes make a return in New Vegas. Perhaps some smaller settlements support themselves by having a gecko based economy, selling the creature's priced skin to the rich people in Vegas and the other factions in exchange for food and resources. It can also be a way for the player to earn some cash and experience in the early game. Maybe even a good karma side quest of gathering gecko skins for a poor family.

Didn't they do that in previous games?

And would be great to see a actual economy this time around.

Forget Karma, we got got factions.

Not the silver gecko in one of the gameplay videos, it ran like a penguin on speed.
Looked awesome.

The gecko skinning was in Fallout 2. Golden skin can sell for more compared to the normal ones. I would like to see an actual economy too. But the player will still have to find a way to earn money somehow.

I think that brief look of the Fire Gecko in the gamechurch interview was on two legs also. Also i took another look of the first shot of the baby gecko, turns out it might be doing a lunge instead of actually being on all fours.

They're both. I saw a couple standing on their legs and they ran at me on all fours.

That's awesome.

Either or , but most definitely bad ass

http://g4tv.com/videos/48105/Fallout-New-Vegas-Senior-Designer-Interview/ at 0:55.