Sean-

While it costs a bit (not much) I've found that having your DNS registered somewhere other than your ISP solves problems related to downtimes and switchovers of your ISP. That way you can just switch your host when you want and not have to worry about the handoff of DNS at the same time (which always seems to take forever). I think I remember you mentioning this is related to your field so this is probably not that insightful.

Jason