Ask YC: How do I promote a web app to bloggers?

I created a simple web app (Mytipnetwork.com) that lets a blogger create a page where their readers can tip them off to interesting stories, images or clips that they find on the web.

example page http://www.mytipnetwork.com/n.php?site=adtoferlnn

It works pretty simply you add a tipbox image to your page that tells you and your readers how many tips you've recieved today from them. And you can respond back by saying what you got tipped by(meaning heard for the first time and/or found interesting)

As a tool, what I thought it might achieve is help bloggers get inspired to their next blog post by their readers.

Problem is I don't have a blog, I don't have friends who are bloggers, and my only available currency towards promotion is time and energy.