We are talking to many marketing people who are using - or at least thinking about using - tools that can help them track, record, and target website visitors.  There are a lot of tools! 

Here is a great list and summary of who is offering what.  There are plenty more but this gives a nice summary.  If you are like me and just getting your head around who offers what then it's a great start.

If you're interested in seeing who is using what to track you when you visit their site then download the Ghostery add-on. Have a look to see what your competitors are doing.  It's a neat tool.