Same here. I have done a tri. I can swim (and my local pool has a "punch-12 card" that let's me buy 12 swims for $60 with no expiration date - ideal for the one or two tri's a year I intend to do). I just don't. Often. Plus, for me, it's too much time and hassle to fit in training for 3 sports when I have a full time job and want to live a life other than training.
I've done several du's this past year. I enjoy the challenge. I don't know how much I train for them other than doing a run-bike-run workout with my tri club and an occasional brick workout. I alter riding and running on different days. I just try to maintain a healthy eating habit (hard when you never met a cookie you didn't like). I don't think I really need any special foods for a sprint distance event. They're generally over and done within 1.5 hours. I suppose I'll have to learn more about in-race eating if I intend to do a longer distance du next June (10k Run1, 70k bike, 10K Run2).
2007 Seven ID8 - Bontrager InForm
2003 Klein Palomino - Terry Firefly (?)
2010 Seven Cafe Racer - Bontrager InForm
2008 Cervelo P2C - Adamo Prologue Saddle