MemWallet is a deterministic cryptocurrency address generator, like WrapWallet, but it works for Ethereum, Litecoin, Monero and Bitcoin. You never have to save or store your private key anywhere. Just pick a really good password - many random words, for example - and never use it for anything else.
Given the same Passphrase and Salt, MemWallet will always generate the same address and private key, so if you only need to remember your password to access your funds.
For more information on why this is safer than a regular brainwallet, see WrapWallet's help, MemWallet is a re-implementation of WarpWallet, but it works for other currencies. WarpWallet and MemWallet use the same algorithm, so WarpWallet and MemWallet will generate the same Bitcoin address for a given Passphrase and salt.