Swim: Wetsuit, goggles (Aquasphere Seal Mask XP), cap (provided by race), and tri shorts/tri top under.
Bike: Tri bike, helmet, glasses, shoes. Might add a Gu or two if it's a longer ride.
Run: Glasses (same ones I rode with), running shoes.
The only things I really change for longer distances is maybe the running shoes, and maybe add socks (depends on what running shoes and the distance). Carrying nutrition (seems strange to me to call Gu "nutrition") is the big difference -- for a sprint I won't carry any, for an Oly I'll have a Gu.