I was looking a the Pownce API this morning and found their Pownce Integration section. With a simple link you can add a "post this link to Pownce" button to your blog.
Just add this simple link to your template:
Be sure you escape encode your link and headline. Any link or headline with an & or # in them will not post properly if you don't.
You'll find all of my "post this" buttons (what I've been calling "blog buttons") just above the comments section of this post.
Here's the small Pownce button I'm using:
PS: I've added Pownce to my social links on the left. Since Twhirl now lets you post to Twitter and Pownce at the same time, you'll see a little bit more from me in Pownce.