Credit reallocation and credit limit increases

When searching and reading Fatwallet Forum, I learned that it is possible to reallocate/move existing credit limits between multiple credit cards from the same credit card company. So if you received a 0% balance transfer offer, it maybe possible to move existing credit limit from another card and receive a higher transfer. When doing this it is important to consider keeping old credit cards (even just with a minimal credit limit) around, as having old credit lines in good standing does help your credit score. As a sidenote, if you have your cards registered on the credit card company's website, it maybe possible to request a credit limit increase just by clicking on the "Limit Increase Request" button, and in some cases no additional information would be requested, and no credit report pulled.
Some other sites of interest are CreditBoards Forum, Credit Talk Forums (for credit related questions), FlyerTalk, Credit Info Center, Debtorboards and Creditcard Perks.