Grouping Buffer Selections

[Joe Riel]

Is there an extension that allows organizing buffers into 
related groups such that, when manually selecting a buffer, 
only the buffers in the currently "active" group are
displayed (with, say, C-x C-b)?  

I currently use bs-show (and iswitch-buffer), however, when
working on different projectes in one emacs, it would be
nice to group the buffers by project and have a smaller
set to select from.

-- 
Joe Riel