I have crossed it on the ferry (before the bridge was built) and we actually went through Zimbabwe while crossing the river. That's how short the border is.
The Top Gear episode in Botswana is probably the best show they ever made. My wife even enjoyed that one. Oliver was awesome. My German grandmother in law had an Opel Cadet that my wife remembers from her childhood.
Beautiful country, I recommend visiting. Friendly people and lots of wildlife, especially up north. It's also pretty cheap (at least compared to Australia). It ranks just outside the top 1 on my favourite countries list, just behind Australia itself.
Namibia ! I swear I meant Namibia !