A Different Kind of CPU
Not a computer processing unit, but a contract postal unit. Nook and Cranny, located on Kailua Road near The Bike Shop, is a place to arrange for professional house cleaning, and (as of this past Christmas season) on of 16 CPUs on Oahu.
Although they are closed for an hour at lunch, they open at 7:00 a.m. and the "big post office" doesn't open until 8:30 a.m. It is convenient, friendly and usually not busy.
The folks at Nook and Cranny love stamps and so will always alert you when new ones are out -- like the cool Olympic postage stamp (pictured here) which was designed by Hawaii's own Clarence Lee.
So -- if the line is too long at the BPO, turn around and go to the CPU.
P.S. For now, they only take checks or cash but they are working on getting charge cards set up.