Does Bytecoin use SHA-256? Also, doesn't this mean that I can use hardware such as a bitcoin usb block erupter to mine it?
Bytecoin (BCN) bytecoin.org uses the CryptoNight algorithm and cannot be mined with bitcoin mining hardware.

Bytecoin (BTE) bytecoin.biz uses SHA-256 and it can be mined with a block erupter (and any other bitcoin mining hardware).