There are exactly 242 ways to send money to someone over the internet now, but Square thinks it has found an angle no one else has worked yet. Square Cash is a new way to get money from your bank account to someone else's, and it relies on sending an email. Not impressed? The thing is, that's all you have to do.
To use Cash, just send an email to the person you want to give the money to with the amount in the subject line, and make sure you CC firstname.lastname@example.org.