http://www.buzzshout.com/http://www.launchfeed.com/
Social networks on Ning with collaborative blogs - write posts
Google Ad-words
Put a link in your email footers
Make some good comments on Techcrunch with a link to your site
I don't think I've gotten more than 50 hits from a TechCrunch comment, and that's when I get first post. It still won't hurt to make as many comments as you can on popular blogs with a link back to your site.
commenting on blogs is a great idea, but you do that to connect with the blogger and making him realize he might need to write a post about you. you don't comment on blogs to get traffic. and anyway, comments have all rel nofollow on them