Microsoft has a Beta version of their own Anti-spyware product available for download. (You'll need to use Internet Explorer to download the thing, I'm afraid)
http://www.microsoft.com/athome/security/spyware/default.mspx
I'm interested to hear the experiences of anyone who has used it. How does it compare to the likes of AdAware and Spybot for ease of use? How does it compare for effectiveness?
What other matters are worth commenting about in relation to the product?