I have a Canon G2 which is about 28mm on the wide end. But my experience
with interiors is that you need WIDE, as in as wide as you can get without
fisheye effects. You can get many P&S types that will let you put an
adapter that you take a quality hit, plus the cost you might as well invest
in a dslr.

... for shooting interiors (for real estate webpage)

I know this can be done with a digital SLR, but would prefer not having to
go to
that expense. Are there any other options??