"Snoopy": Lots of them (and a whole lot of other types of software):

http://www.econsultant.com/i-want-freeware-utilities/index.html
http://www.econsultant.com/i-want-open-source-software/index.html

Sorry, I can't recommend one of the "Anti-Spyware/Anti-Virus/Anti-Rootkit" because I don't use them (my connection to the internet is through a Linux machine which has its own firewall).