OK, this is getting ridiculous. I've had six flats in the past week. One was because I didn't install the tube correctly, but the others have all been small punctures. I've turned the tires inside out and gone over every inch of them to find any thorns that might be sticking through on the inside, and I used an air compressor to clean the surfaces of the wheels and tires before installing tubes.
So, is it worth spending the extra money to buy tubes that are supposed to be more rugged? The two I'm aware of are what my LBS described as thorn-proof or thorn-resistant, which looked and felt like they're just thicker rubber. Then at Wal-Mart I noticed they sell a couple different kinds of self-sealing tubes (I think one was called "Slime"). Any thoughts on these special tubes?
My tires have less than 1000 miles on them, so surely I don't need new ones already.