Piwik [1] is a great alternative to Google Analytics. It is free, open source software, and it is typically self-hosted.

While I do not think it supports Do-Not-Track at this time, Piwik does have configuration options to respect emerging laws on data protection and user privacy.

[1] http://piwik.org/blog/2011/03/piwik-can-be-used-in-complianc...