I do - my personal email (I have my own domain) is only given out to personal friends and with the explicit instruction that they better not use it to sign up to competitions or 'tell a friend / share the reward' forms. Some still do of course, but at least gmail's spam filter filters out most of the junk.

For any 'commercial' site or correspondence, I create a unique alias. Well 'create' is too formal, I simply have a catch-all address so I can create 'aliases' on the spur of the moment. I rely on gmail's spam filter to filter out the rubbish and if a particular alias becomes 'compromised', I can create a custom rule that deletes email received at that particular alias.