for each domains i have one emails a/c so all together i have around 20 email address most of them are gmail.
I only use one Yahoo! email address because I've been using it for years and people to whom I communicate via Yahoo! Messenger still send me emails on that old Yahoo! address (they think that having an Yahoo! Messenger nickname involves having also an Yahoo! mail address). OK, a gmail only for newsletters. A gmail for personal use (friends & stuff). 3 old gmail address to keep just to maintain touch with old friends. If they use that address, the mails get automatically forwarded to my standard email address. That's about it.
I have about 10 actively used email ids. Half in my name, the rest in fake names. Whenever I have to enter my email id in places I don't trust, say for downloading programs, I use my fake ids. Except 2 (one in yahoo and one in hotmail), the rest are in Gmail. BTW, I recently signed up for Google Apps. So I have one personal Id there too. The contents of all gmail ids (in my name) are forwarded to my primary id.
I may have many many many more on diffrent domains ... only two things are common "PASSWORD" and "I OWN THOSE"
Good question?! I must have at least 25 for each domain I work with.. Then at least a bunch of personal ones and some forgotten ones...