I second the Luggage Works/Purdy Neat bag, but if you're a commuter, I would definitely go with the 22" bag. On the 737/757/767, the 22" will fit wheels first into the overhead (I don't know about the 88). The 27" requires you to put the bag in sideways. With overhead space always being at a premium, you might have trouble getting that 27" on board and end up checking it.

I've never had trouble packing for 5 or even 6 days with my 22". It's amazing what you can cram into it. You can also buy an extra small bag that attaches to the main bag for those times where you can't fit everything in. I don't have one and I've never had a need for it.

http://www.luggageworksonline.com/CL...-164-96-196-46