I have seen Jajah, PageFlakes, Printingforless.com, and Squidoo releases on PR Leap.
Just to mention someone we can all recognize. But it's pretty well-understood that PR (not just press releases, but the whole process) is more valuable than any amount of advertising that small companies can afford.
It still amazes me that the most worthless of sites can effortlessly surpass the traffic of good ones with a couple easy press releases.
The answer is to develop a press list and contact them individually.
And it'll do no good to send your press release to my Mother, she wouldn't want it.