I am a programmer at a very large corporate company where I have a number of usernames and passwords. I have a user for the company intranet web experience, the company mainframe, my department's LAN and e-mail system, and a number of other usernames and passwords for various other items (the OLD e-mail system to access systems that haven't been ported to the NEW system yet, the dev, test and production databases, our department's wiki, my Flexible Spending Account through the company, access to our health and benefits division, etc.).
It's a lot to keep track of. *to be continued*