Excellent list of resources Michel.
I know web analytics isn't a productivity tool per-se, but now that Google Analytics is open to everyone (there used to be a waiting period) I see no reason why everyone isn't using them.
http://www.google.com/analytics
Just to put this in perspective - When it was still Urchin - they were charging $500 a month. Then when Google bought them they lowered the price to $200 a month - and then it went free.
I do not know of any other free web analytics tool that even comes close to what you get with Google Analytics.
- Ophir