How to combine several small repositories into separate subdirectories of a single repository?

[Marcin Kasperski]

As people mostly describe pulling here, let me note that convert is in
fact fairly nice. 

I'd convert individual repos to rename files into subdirectory, then
pull them all. This would make nice layout with proper hg blame and
easily available individual files history.

This is mostly about creating short spec, like (say it is my.map):

    rename . subdir

and then 

    $ hg convert --filemap my.map       source/repo  target/repo


Apart from renaming one can also include/exclude to pick what is taken.

Internally this is like replaying all commits.