No problem, I broke down and bought one on ebay
So - can I assume I am immune to any Verizon roaming charges as they don't have any towers out in the UK/Ireland that the Droid can communicate with?
Since you'll be in Europe, I doubt it will be an issue since you'll likely not find any CDMA networks there.
The big whammy is data. As long as you follow the directions for turning off the data connection, you'll take a way a lot of the risk.
When I was in Japan, I did have CDMA roaming coverage part of the time (my data was turned off). I never answered or made a call on the cellular network, and never sent any text messages. I did receive a couple of text messages, and there is a charge for that but it's pretty small. I think my verizon bill was about $1 more than usual.
If you don't answer or make any calls, you'll be fine. Text messages can't be stopped from receiving, but the cost of those is pretty minimal.
But again, you won't have coverage at all likely, so it shouldn't be a problem.