Yep, Gatorskins are awesome at flat resistance. They're supposedly not the best "feeling" tires, though I can't say I've noticed that myself.
Vittoria Randonneurs were great (one flat in about four thousand miles) and lasted for freaking ever, but it appears that there's only a more tready Randonneur Cross model available now.
After using those two tires, I feel like I'm tempting death with these Open Corsas, but I've only had one flat so far in, I don't know, 1000-1500 miles? Which is good, because they might as well be glued on.
As for supplies, I keep at least a tube, levers, and a pump with me, though I've added a patch kit recently, and scampered back to the holy Road Morph from the small, convenient, and disappointing Crank Brothers high-volume/high-pressure pump.