Tom has a write up on this one:

Which he sells.
Buy This for Your Triathlete. New Improved '05 Model in stock NOW! Call (313) 278-1350 to order.

Every race morning I used to have this nagging feeling that I forgot something. Did I have my shoes (both pairs)? What about extra swim goggles? Ear plugs? I can’t remember if I packed my helmet and sunglasses.
After a couple hundred triathlons I learned a couple tricks for packing and remembering the gear you need. I also learned how to keep your packing simple so you didn’t have to sort through a lot junk to find what you need in a hurry- like spare goggles ten minutes before your wave start when your strap breaks.
The right bag is everything. If you have the right transition area bag and pack it the same every time as well as using a written checklist you’ll never forget anything. 
Our favorite race bag is the new Jandd Mountaineering transition bag. Jandd spend an entire season on the triathlon circuit testing prototypes of these bags with triathletes around the U.S. This is the final design based on their feedback.
Jandd Mountaineering makes backpacks for high altitude mountaineering, bike bags, soft luggage and related items. Everything is hand-made here in the United States and designed by Jandd.

The Jandd Transition Bag has six compartments. With two shoulder straps it carries over one shoulder or like a back pack. The big main compartment is about 2,200 cubic inches and will hold all your race clothing, after race sandals, wetsuit, towel a change of clothes for after the race and some other items. There is a small key/wallet/cell phone zippered compartment at the top of the main compartment so you can find your USAT card quickly at registration or get to your keys in a hurry.

The top of the main compartment opens with a large draw string giving you easy access to everything in the bag. Very nice. It’s easy to get to the stuff in the bottom of the bag from the top.
The front of the bag has an excellent helmet carrier that snaps your helmet securely to the outside of the pack. This is nice since you an pull your helmet out quickly, put the transition bag on your back (it’s a backpack) and wear your helmet while you ride to or from your hotel or race parking lot.
There are two side pockets for running shoes and cycling shoes. Cycling shoes go in no problem but a big pair of size 13 Air Maxes would be a tight fit but do make it if you smush them together heel to toe, top to top. Putting the shoes in their own compartment is smart since they don’t get the rest of your clothing dirty. My size 10 Saucony Hurricanes fit perfectly and my racing shoes fit with room to spare.
The bottom compartment has a full length/width zipper and mesh side panels. This is where you put your wet stuff, including wetsuit, after the race. The mesh provides some ventilation so it won’t start growing things in there.

**** **** **** It is also on my short list of stuff I need. Note I do not work for bikesport nor do I have any affiliation with them. I just knew where to get a cool bag.