we just got crunched ourselves yesterday (see: http://www.techcrunch.com/2008/04/16/soocial-makes-plaxo-loo...). we tried to get techcrunched a year but that was way to early (hindsight).

pick the moment you know you are up for it and then make sure you visit an event where some editor of techcrunch is and give them a demo. face to face contact really is so much more powerful than an e-mail from a stranger. thats how it worked for us, anyways!