After looking at both websites, I think I will join AIPB myself. The primary reasons being that 1) their certification process is a nationally administered test while NBA does an on-line, open book test

, 2) the continuing education component looks better at first glance, 3) the "help desk" option appears to be a valuable resource for bookkeepers

, and 4) the AIPB annual membership fee is a third of NBAs but offers as much, if not more, value for the money.
Thanks for the resource - I hadn't considered membership in a bookkeeping association but it makes sense since I am a bookkeeper for a living