Google Analytics has come a long way from days of realizing "It's free so it doesn't do fancy things like click stream analysis" and needing to resort to SiteCatalyst as the best option for doing that. There's a whole lot you can do with Google Analytics if you have advanced programming skills in-house or under contract. For some fine examples and a relatively non-techie-friendly description, consult the Google Code documentation for Google Analytics. Here's a direct (shortened) link to my favorite part, Event Tracking