Web Mash Ups - Using other people's stuff

How many web sites out there let you "embed" some of their information into your own site? What new things can you do, and more importantly, what benefits can you receive from such "mash-ups?"

The June Houston Web Design Meetup will be talking about that very thing. I am still looking for a presenter (I'd like to have a bit more content before adding activities) but no matter what, I promise you will come out of this meeting with something web related your didn't know before (no matter what level experience you have)

My offer: free beer!

Your Requirement: bring in one or more examples of web site that let you "embed" something from their site on your own. Even better if you can bring example source code (HTML, Javascript, or something more) to share. Adding the weather to your page DOES NOT COUNT :)