Hi Coyne,
Hmmm...I can't say I know much about HNL deals in particular. Does you friend need all around info about HNL, or just info on a hotels? If it's just hotels, and your friend is looking for "cheap", try the Marine Surf, on Seaside Avenue. It's just 1/2 block from Waikiki, and in a very safe and central location, but, it's also very low on frills, shall we say. Phone number is 808-923-0277. If your friend happens to work for United, there is an annex next door, which we just call the Seaside. It's basically owned by United, just for layover crews, but several years ago, they started renting extra rooms to United dependents. They may even rent to other airlines now. The last I knew, they still didn't rent to the general public, which was great for us! I haven't been in there in some time, but I like the rooms much better than the Marine Surf. It just seems like the quality is higher, but still no frills. You can call the number I gave you, and ask for the front desk next door at the Seaside.
For a fabulous dinner, not to be missed, go to the Colony Surf (condo building) at the base of Diamond Head, to a restaurant called Michele's. It's my favorite thing to do on Oahu. Don't fail to order the Crepe Suzette, made right at your table. Another popular thing with crews is to go to the Halekulani for sunset, pupus, and hula entertainment. It's not cheap, but is very enjoyable.
One last thing that just came to mind--if you will go over to the Seaside, especially in the early morning, that's when all the crew members are drifting down for morning coffee, breakfast, and exercising, and the lobby can be a rather energetic place to get some more up to date pointers.
Aloha, and happy traveling.
Adrian