Well, I bought two new tubes for my bike yesterday. Went home and installed a new tube in my front tire; however, before installing it, I inspected my tire. I turned the tire inside out and ran my hand gently along the inner surface. What I found shocked me! I found a small piece of metal (imagine a leg off a normal office staple). When I turned the tire over and started looking for the end to pull it out, it was almost impossible to see. But, I found it and removed it. I think I have the tire issue fixed for a while now.
Oh, I also took my old tube, cut out the valvestem and put it between my tire and new tube. My hope is that this will serve as a bit of protection from these types of punctures in the future. The guy at the bike shop suggested soem kevlar strips (they are stronger) to do the same thing. I didn't want to spend $16 for those just to turn around and buy new tires.
I'm thinking about buying tires more suited to street riding. From what I have read, they will have less resistance and allow me to go faster with less effort. I'm all for that!