It appears to be Trebuchet Bold.

I know it's an old story, but I love how type designer Vincent Connare comically named Trebuchet after medieval catapults.

Right on. Thanks John! Do you have a link to that story?

It appears on this page at Myfonts.

One more question. Is Trebuchet a font available on most systems? I've noticed it just tonight on several blogs.

Trebuchet is considered one of the Microsoft Core Fonts for the Web so yes: it can be found on almost every personal computer.