Include *TIMELY* 3rd party RSS content in my posts?

I want to include 3rd party RSS content in my posts and RSS feed, but I’m not sure how to do this effectively.

Here’s the kind of thing I’m after.

1. I make a new post in MYBLOG (POST1), and the latest post from OTHERBLOG is included at the tail of the post (OTHERPOST1)

2. I make a new post in MYBLOG (POST2), and the latest post from OTHERBLOG is included at the tail of the post (OTHERPOST2)

3. I make a new post in MYBLOG (POST3), and there is no newer post from OTHERBLOG so OTHERPOST2 is included in this post.

The problem I have executing this is that, because the pages are dynamically generated, I will end up with something like this:

POST1 (OTHERPOST2)
POST2 (OTHERPOST2)
POST3 (OTHERPOST2)

Also, this has the effect of resetting my RSS feed (because every time a new post is added to OTHERBLOG, it changes the content of the posts of my blog).

AGH!

Any ideas?

Thanks,

Gabe