hg branch == bzr ???

[Stefan Ring]

I worked with Mercurial quite a lot recently, and I really like this 
"internal branches" feature. It can be very confusing at times, though. 
Bzr's philosophy is completely different in this regard -- it can only 
handle one single head in every repository.

In your case, I would create additional repo directories somewhere 
outside your working directory and always push into them after 
committing. Then you can switch to any of these with pull --overwrite.