Personally, I don't generally take action against probes. If I tried to
deal with all the probes we get at work I'd do nothing else (having one
of the CA domain root name servers is a bit of a target).
For my own machine I just make sure I run as few services as possible,
strip inetd.conf down to the minimum, and run packet filters to further
reduce the risk of some unknown service making me vulnerable. Oh, and I
don't use IRC -- that seems to be all too common a thread here...
Brian.