What amazes me is how small the fob is. Compared to my SecurID card, it's tiny The single button on this device shows the current active code. 30 seconds later, the display goes blank and you press the button for another key.
You can get a sense for how this works by looking at the activation process for PayPal. The serial number of the key is tied to the physical device. The activation process requires you to enter two keys from this device, spaced 30 seconds apart. This is to ensure we have the key and ensures the key is synchronized with the authentication server.
The one thing I was wrong about regarding these PayPal Security Keys is who made them. Apparently, the tokens are made by a company called Vasco. In the end, it really doesn't matter. What matters is that the technology makes it very easy to secure your accounts on PayPal, eBay, and other services thanks to Verisign's Personal Identity Provider.
Have you ordered your fob yet? Have any experiences? Share your thoughts in the comments.