I just came across this new method of sending payments that should rival PayPal - TextPayMe.  This new service allows you to send money to anyone through your mobile phone via SMS. You just text 'pay <amount> <phonenumber>' to TextPayMe's 5 digit number. You will then get a phone call back confirming that you really wanted to send the payment and then you authorize it with your PIN. The two forms of security are 1) the confirmation is sent to your phone and 2) you have to know your PIN.

They're also running a special if you sign up now during the beta you'll get $5.00 added to your account and are guaranteed to never have any transaction fees - for life!  You'll also have a chance of winning a new XBox 360.