Re:Well... (Score 4, Informative)

I've had similar experiences. I've noticed several SSH attempts on my server recently - just a personal server at home. I've written to the abuse addresses found by running WHOIS and politely informed the ISP that there was an intrusion attempt and could they please inform the user that we are not a public service.
Many times the ISP has responded and usually their customer has a zombie box.
Always include a log if possible so they know the time and the IP-address. Remember to tell them what timezone the timestamps are from.
WHOIS links
http://ws.arin.net/cgi-bin/whois.pl
http:/ /www.ripe.net/db/whois/whois.html
http://www.apni c.net/apnic-bin/whois.pl