In the geth console:
eth.sign(eth.accounts[0],web3.sha3('yesyesyall'))
Returns: "0x6df4a058e304c2e42032e6b812e268f4d4d4006698f41a2345ed88a161b00e52176b333fb5945dc02e860a4e9c29351eccba19316a82bf86530b977d4629efcf1c"
How do I verify that was signed by eth.accounts[0]? Everything I see online mentions contracts.