Time ago I played with Beagle (apt-get install beagle), but after its 0.20 release decided to build it from sources. I don't do apt-get because I'm running mono from svn, yes, I know can have parallel installations but like living in the edge ;-). Compiling takes sometime, allmost all the time because of the dependencies, if you want to enable everything you must compile allmost all. Here's my quick-and-dirty guide for building Beagle 0.20 from sources.
I'm running linux 2.6.12-9-686 from deb package with Ubuntu Breezy. Guided from beagle's wiki-page I began installing. Remember that using another --prefix rather than /usr is a very good idea, I use /opt/beagle/, remember to set $PATH, $LD_CONFIG_PATH and $PKG_CONFIG_PATH while installing the packages,
Then, beagled, and beagle-search, and done.