Time stamping

In my opinion, a general time-stamping service would be of great utility at times. I'm aware of some projects that try to utilise the Bitcoin blockchain for that purpose, by sending coins to addresses based upon the hash to stamp or encoding the hash into amounts sent or things like that. While that works, I don't think it is a good idea to abuse Bitcoin for that purpose. After all, it was made for payments and not general-purpose time-stamping.

So instead, we could set up a genuine service <b>only</b> for time-stamping, with a separate blockchain. It could work similarly to namecoin, with merge-mining to get easy hash power as well as a dummy currency that can be earned by miners, possibly traded a little but whose main purpose is to pay the network for special time-stamp operations. (Either in form of a network fee as with namecoin or just by transaction fees.)

What do you think about that, would that be a useful project? (Opposed to all nothing-at-all-changed altcoins that are only used for speculation.) I think it is a useful thing to have, and it would be good to keep such things off the Bitcoin chain.