PayPal plans payment over cell phones via SMS

Paypal is reportedly testing a new offering that allows consumers to make purchases and money transfers using simple text messaging through mobile phones. The service, known as PayPal Mobile, will be launched in the next couple of weeks in the United States, Canada and Britain. Paypal is hoping this new service will provide a bridge between the worlds of e-commerce and brick and mortar stores. My first question would be how safe will this be? Is SMS a secure means of communications? SMS messages are sent in clear text. Will you login by simply sending a text message with you username and password? I hope everyone understands that a text message is saved on your phone when you send it. Have you ever misplaced your cell phone? Imagine this, you can't find your cell phone and the next thing you know you are broke. Scary, isn't it.