We have developed a new web app:

http://stampd.io

It allows the blockchain time stamping of electronic documents containing any kind of digital content:

 - No account creation or login required

 - A pdf certificate is issued and emailed to the user after the stamping has two confirmations on the blockchain. The certificate contains all the appropriate technical details which explain the methodology of the user's particular stamping. This allows the user to prove the stamping at any time in the future without referring to any centralized service (including ours). See template here:

http://stampd.io/wp-content/uploads/2015/02/stampd_PDF_Receipt_Sample.pdf

 - We have allowed for a tiny cost per stamping to ensure both (a) avoidance of bloating on the blockchain and (b) coverage of our server expenses & miner fees.

We would appreciate any comments/impressions!

The stampd.io team