It turns out that Helger Lipmaa who maintains a cool compedium of Crypto Links as part of that also has a List of links related to Time Stamping Services.

My Neubia project which will be explained more here as we go a long is quite reliant on TimeStamping Services.

A TimeStamping Service is kind of like the Digital equivalent of a Notary Public. Basically you give it some data and it signs it with a timestamp.

This means that you have independent 3rd party verification that what ever it is you had signed was as you say it was at a given time. These kinds of services have many different applications. Many of which I'll probably get into in a while.