This will be a continuing battle between ISPs and the spammers. The thing is that the ISPs can only react most of the time after the fact so there is always a small window of opportunity for spammers to hit your inbox. You can help by using the email filters that your ISP provides and when one does get through flag it so that they can update the filters. When you do get a message don't click on the 'unsubscribe' button if it is provided or don't reply to their 'unsubscribe' email address if provided. All you do is confirm that your account is live and we can almost guarantee that you will actually receive more spam rather than less.
I may be paranoid, but, keep your anti-virus, anti-spyware and firewall up-to-date. These spammers may also try to embed scripts or auto-launch programs that will install software on your machine and take it over and add it to their bot network.
You can look at ClamAV, Malwarebytes anti-malware as a starting point for your securing your systems. Secunia also has a good package called PSI that will scan your system to see what is out-of-date, vulnerable, etc and allow you to keep your system-up-to-date. I use these on my home PC when I start up the dual-boot system to run Vista and not Linux.
Update (2009/09/22):I am now running AVG on my Vista partition. It seems to do a bit better on the detection of malware and does not impact the performance of the machine in any noticeable way. I will be still keeping Clam on the Linux portion as I can then use that to scan my external HDD or USB sticks while staying in Linux.