https://wishlist.yahoo.com/

Yahoo is cleaning house and recycling usernames. You can try to get yours prior to August 7, 2013. You get 5 suggestions to work with. I wonder if there are any good usernames out there that could be exploited. 

Claimed my old nick, got a welcome back message from Yahoo, it does not open. Says it all.

Does anybody want to team up on launching a service where, for a small monthly subscription fee, users can enter the nicknames they want preserved so that the service regularly logs in and imitates user activity?

Sounds like a good opportunity for third-world arbitrage.

You'd only have to run the script once a year. Sounds like a winner in terms of resources.