Google will only index one URL when you have multiple URL's pointing to dupicate or mirrored content.
We have a url that is currently only partially indexed by Google (www.ni.com/matrixx). However, instead of indexing and crawling this URL, Google has chosen to index and crawl www.natinst.com/matrixx - a URL we do not activly use. (Since our site, years ago, was www.natinst.com, we still maintain those URLs, but they all redirect to ni.com URLs.)
Well then google knows about EVERY URL you visit.
Yes i DO have google toolbar, and yes i do have the advanced features turned on so it reports back.