I was pretty excited when I heard that Colbert would be on O'Reilly, and O'Reilly would in turn be appearing on Colbert's show. Click the link below, you can see both interviews. They're actually a bit dissappointing. O'Reilly makes a bigger fool of himself on his own show than he does on The Colbert Report where he actually keeps a fair sense of humor, but in the end O'Reilly is too cautious to fall into Colbert's trap and it wasn't the fireworks I'd hoped for. That said Colbert did get off a few good jabs.
Here's the link, enjoy.