I got a bulge on my front tire, a Specialized 700x26, rated for 100 psi. It only had 200 miles on it. I have to admit that I slightly over-inflated it to 110 psi. Weather has been very hot, which may be a factor. I also weigh 280 pounds, which didn't help the tire any.
I might have run over one of those cast-iron water main valve covers, and I also rode over cobblestones.
The bulge was kind of "S" shaped, a little bit on one side, then on the other side an inch away. Examination after removing the tire from the rim shows the threads of the tire casing were pulled apart in the center of the tire , not on either side. Damage was about the size of a thumb-print.

Resolution of this dilemma:
I went back to the LBS and bought a new tire. The new tire is the same brand, Specialized, but it's the "Expedition" model, 700x32, rated for only 75 psi.

I haven't ever had much luck with "skinny tires", I went back to them very recently, after using other bikes with tire widths in the 1.90 to 2.215 range. I had frequently run my Mountain Bike over-inflated to 90 psi. My BMX based lowrider has 20x1.90 "Hook Worm" tires that take 110 psi with no problem.

Are there any 700x26 tires out there that can take more pressure-say 120 psi or more?
Please let me know.