How many Email Addresses are Too Many?

I currently have 4 email accounts that I check regularly.

1) An Outlook account for work.
2) A Yahoo! account that I use for social emailing and forwarding pictures of inebriated, passed out people with magic marker all over their face, tied up with duct tape.
3) An MSN account that I use to collect spam but also look through ocassionally.
4) And finally a Gmail account that I have just to have (although I want to start using it more often because of the new themes available http://gmailblog.blogspot.com/2008/11/spice-up-your-inbox-with-colors-and.html)

How many email accounts do you use?