Just like any code repository, this contains the latest code I have commited. Even though I attempt to commit only when at a known happy point, it could be broken. I suggest using an official release unless you know what you are doing.
svn checkout http://bobmajdakjr.googlecode.com/svn/trunk/pgid3 pgid3
It is possible to get v2.1 directly from SVN, like so:
svn checkout http://bobmajdakjr.googlecode.com/svn/tags/pgid3-2.1 pgid3-2.1