Pair Programming with VNC

Dietrich Kappe writes on the Agile Ajax blog on surmounting the difficulties of pair programming when part of your team is offshore. Interesting stuff, but Dietrich, you also made the offhand comment that Test Driven Development is one of your commandments as well. What's your process for writing Ajax unit tests, and if you're not always doing continuous integration, how do you know your tests are always passing? I'd be curious to know!