Interesting approach to tracking how spammer’s have found your address if you have a gmail account, though it does have a flaw. CamZak.com / Google hack: Stop spam with ‘Infinite’ e-mail addresses with GMail
I have been doing something similar for years with my own domain and a catch-all address. Of course, having a catch-all address itself attracts lots of SPAM, but those end up being relatively easy to filter as they come in.
One problem with the gmail method is that if it became popular, spammers would figure it out and simply drop the post-plus portion. Therefore best way to use this effectively, is to always use a ‘+something’ for your personal emails.