Wow, I'm sorry we'll miss each other.
Yes, there two major rides here on the island, clockwise and counter-clockwise. :-)
It really depends on how much time you have and how much distance you'd like to cover. I don't know how much interest everyone on the list has in rides on Oahu so we can continue privately but there are somethings to note...
We had a decent bus system and all buses have space for two bikes. Thus if you want to bus to a start location, or back from the end of a longer ride it's possible (and I do it all the time).
The most scenic routes are on the windward and north shores not in Honolulu, though exploring the city on bike is easy and the waterfront is very bike-able.
We can also do flat (Pearl Harbor bike path skirting the edge of the water most of the way around).
My favorite bits:
1. Honolulu waterfront (I do this more or less daily) - short, add around Diamond Head for even more fun and views
3. Kahaluu to Haleiwa - normally I just ride Honolulu to Haleiwa and take the bus back, but at 80 miles it's all day when you toss in lunch at Uncle Bobo's in Kaaawa.
Just to keep this Riv worthy, I've ridden all of this (except Tantulus) on my Quickbeam without stopping to change gears, even the hills and there are some (all told about 2500 feet of gain - not much but uphill into the wind at Makapuu is...um...interesting).
If you let me know off the list how much time you have I can make specific suggesting and let you know where to startt. Indeed I've probably mapped it with gps and can give you the links.
Aloha and again, sorry we'll miss each other. I was going to see what you were up to while I'm in the Bay Area as well. :-)
Bob
René