bundle start order and service listeners

[Benson Margulies]

I'm about to write code in which I set up blueprint injection of the
bundle context so that I can obtain a service. It occurs to me that
I've seen, out of my peripheral vision, some talk about issues of
start order: how to I ensure that my bundle goes looking for the
service after the source of the service registers it? Do I register a
service listener, and defer initialization until it sets up?