Can I use a butterfly-labs miner to mine any crypto-currency?
Look at http://dustcoin.com/mining. The currencies designated as having SHA-256 algorithms (e.g., Bitcoins, PPCoins, Namecoins, and Devcoins) stand a good chance of being mined with BFL-like ASIC mining hardware. Remember, some currencies support merged mining - mine once and get paid in multiple currencies. Either your centralized pool supports merged mining or you have to do it on your own.