As I started playing with Motorola’s SDK, I realized there was little to no mention of a phonebook API. Some more poking around revealed that it was not present in the JARs associated with the emulator.
Turns out that the materials required to make use of this API are only available under NDA from Motorola. And for some random yahoo like me, that process is started by filling out a questionnaire on the Motorola developer site. And as of this writing, submitting that form yields a server error.