Think of it as a value equation: you want the reporters to help you get press and make people think you have something cool on hand; they want something cool to share with their readers.
So, one way to do it is - as most of the comments have suggested - use guerrilla tactics to get to the journalists/writers/topics that are often covered.
But, what if you created or generated something that is really unique and content-worthy? We did this recently with my product, and ended up with an unsolicited TC piece.
How'd it work? We showed-off the types of awesome things our product could do, and it caught the writer's interest.
So, I'd say find a way to show-off why what you're doing deserves coverage, and then take some steps to help get that in front of people (that's where Twitter, HN, etc. comes into play).
Also, quick note, but the traffic you probably expect from TC coverage may not be accurate.