[OT] multi domain web searching

[Minty]

Anyone point me at a web search engine that will let me run a free
text search, restricted to two or more arbitary domains?

Namely, Google lets me search for buffy on london.pm.org with

  http://www.google.com/search?q=site%3Alondon.pm.org+buffy

but I would like to search for "buffy" across london.pm.org, cpan.org.
perlmonks.org and ny.pm.org.  All in one query.

As far as I can see Google ain't up to it...?