Question: I want to have something like bitbucket.org or github (but for mercurial!) on my VDS. I don't need full functionality, but I need it being able to serve repositories, accept changes (with auth!) and creating new repos in one-two clicks in web interface. What can I use? Thanks

Answer: 
I've not tried it yet, but [RhodeCode](http://rhodecode.org/ "RhodeCode") seems to have all the features you'd ever want from a web based repository manager.

You can create new repositories, fork current repositories and it allows you to set up user authentication and access rights.
As described in the article [Publishing Repositories](http://mercurial.selenic.com/wiki/PublishingRepositories) in the mercurial wiki, mercurial has different way for publishing repositories (hg serve, ssh, hgwebdir, hgweb, ...).
Since you need multiple repositories with [push/pull authentication](http://mercurial.selenic.com/wiki/PublishingRepositories#Allowing_Push) then you should go for [hgwebdir](http://mercurial.selenic.com/wiki/PublishingRepositories#multiple) (also described [here](http://mercurial.selenic.com/wiki/HgWebDirStepByStep)).

After setting up hgwebdir, apart from pushing/pulling from the repositories, you will also have a web interface that will look like, for example, the [suckless.org code repository](http://hg.suckless.org/).

As [mentioned by Ry4an](https://superuser.com/questions/115365/bitbucket-on-my-own-server/116343#116343) you can't create a new repository via the web interface.