I found when traveling in Germany and Switzerland that I had to wait about 10 minutes for the latching process to be completed. Fortunately I didn't have to make any calls in either country right away.

I'm excited about the USA service... 5c/minute with no minimum is an solid rate for occasional per-minute use. I can use it with an old dumb phone when I want to sell something on craigslist and have it as a backup phone in my bag in case my regular phone runs out of juice at an inconvenient moment.