So after looking at HUNDREDS of robot projects here and with maybe 1/6 of them being "walkers," I still can't find an example of one that looks like it could climb an average set of stairs in a North American home. Aside from the programming and engineering challenges associated with manipulating it into a narrow stairway and levelling, it seems like having a robot that could climb stairs would be an important task for it to be useful.
I would think that a walker that could do it would need at least GWS 689 style servos for legs, but that might not even be enough. In any case, if anyone on the boards has something like this, could you shoot me a link? I'd like to see what you've come up with.