i have about 3 passwords i use for everything.
i have them 'tiered' in a way so that i have a good idea what site uses which.
tier 1: password for bank accounts, credit card accounts, work logins. wouldn't want this one compromised.
tier 2: hotmail, yahoo mail, cell phone accounts, utility bill accounts. also important, but wouldnt be the end of the world if these were compromised.
tier 3: junk password. for AIM, online photo gallery logins, myspace, etc. any site that makes me register first.