I use brainwallets all the time. My current system is composed of three parts. A salt phrase which I never change, a few passphrases, and a digit area which i simply increment to create a group of brainwallets so I don't have to reuse addresses (I started doing that after blockchain started reusing R values for transactions). So for example, my brainwallet is the HSH256 of "Mypassphrase+Mysalt+0000", "Mypassphrase+Mysalt+0001", ect.
I also use alt-keys to increase the level of entropy, even made a web site to make it easier on myself (also didn't trust brainwallet.org):
http://www.paganmind.com/_BrainWallet.htmlI have a FB page for brainwallets now:
https://www.facebook.com/BrainwalletIf brainwallets catch on much, I was thinking of programming a wallet that is kind of like the Electrum wallet, but instead of a password, you would enter your brainwallet phrase. It would generate a set of addresses based on that phrase by incrementing a counter that is added to the phrase for each address.
BTW, I have a small amount of funds sitting in an old brainwallet with much less entropy than my current batch of brainwallets. Those funds are still sitting there.