Well, since this has taken a turn to why I had another blowout, instead the humorous way I scared the crap out of the poor couple walking, I'm pretty sure it's tire related.

The reason I'm leaning that way is I've been riding LBS bikes since I was 14, and in all that time I've never had a blowout until this summer. So while I'm not saying I'm perfect installing tires and tubes, I doubt I pinched two blowout causing tubes

Even though I said I wouldn't even venture a guess as to what caused this one, I know what caused it and it was a cut on the tube. My guess is the new tires (Vittoria Rubino Pro's) I put on the bike in March have a sharp edge on the inside of the bead, and when I put my new tube in, I'll pull the other tire off, and give them both a shot of sandpaper on the inside of the bead.

I would imagine that'll be problem solved.