The block chain is still parsing away (1 million blocks take quite a while to parse), but it is up now: http://altexplorer.net/chain/I0Coin. My I0C wallet address is jMPDh39NJUGDrfnHTtzcMLnpMcj4tm4MGb.
Hot Wallet: You can simple have the wallet installed on your computer Cold Storage: Use Armory for running the wallet as cold storage for large amounts of coins Paper Wallet: a printed representation of your wallet Brain Wallet: I'm not too sure about this one, but it is based around you remembering a passphrase to access your wallet.
In general I would recommend using an offline wallet for and balance you would be hard-pressed to have stolen, and use an online wallet for day to day use.