Dan - this is the subject of some controversy and debate.

My preferred method is much like what I did in the post above this. That being write a post in one place, and link to it from others. (or post a couple of paragraphs on the secondary site with a link back to the original source for the full story).

Many have heard of, and fear, the so-called "duplicate content" penalty. This is really about entire sites being duplicated in order to deceive search engines. Single posts in multiple places likely wouldn't invoke a duplicate content penalty (at least that's what some "experts" say).

But the search engines *may* "downgrade" one post over another if it's posted in multiple places. Not penalize per se, just not really consider it for search placement.

In an ideal world, everything you post is original. But we don't live in an ideal world.

In short, it is probably OK to put one post in multiple places. It may or may not help from a search engine perspective. It's clearly better to post original content every time, but not always possible.