I have published an update site that hosts Guava (which hosts some of Google's core Java libraries), as an OSGi bundle for you to use in your Eclipse projects.
Before you use the update site, keep in mind: There are some kinks that need to be worked out. For example, it seems I didn't get source attachment right, and I'm keeping the version numbers low until the process runs more smoothly. But more important, URLs are going to change, so it is not a reliable site yet. Only use it to test and provide feedback on the set-up.
Feedback is welcome, but patches and (OSGi/Subversion) guidance will get priority over requests.
The update site URL is at http://guava-osgi.googlecode.com/svn/trunk/com.google.guava.site/. It's got the r03 release, which contains the first binary distribution of Guava.