How Would you promote a Twitter-based app ?

Hi all,
We’ve just launched a polished small app for twitter users, that help them remember things. A kind of intelligent #notetoself, if you’re familiar with the twitter lingo.

Now, the app is not targeted at a very big audience but we’d like to promote it further.

We already have some people discovering it – then talking about it – but we’d definitely like to get more users :)

(it’s free to use, no subscription, btw)

How/what could we do to get more coverage in your opinion ? (ultimate goal would be a tweet from @ev or @jack or @dickc from Twitter talking about us ;) ?

Thanks for the help,