It is virtually impossible due to Sybil attacks. Bitcoin is as close to a decentralised timestamp system as you will get.
nope, can be done. I have a working model. see: http://www.stanford.edu/class/cs240/readings/lamport.pdf
if you review that paper maybe we can discuss how to do this, otherwise I'll save it for later.
later friends! -bm
Very nice! Will have to further review this paper later.
oh and decentralized timestamping CAN BE DONE and it CAN BE ADDED TO NXT. 
-bm
-bm
Read my mind
In fact I think it was one of your posts that lead mthcl to start talking about it with us.. which lead to this post.