Continental Gatorskins come in 27". Some people don't like the way they ride. Schwalbe has several offerings and the Schwabe Marathons are really tough, but not slick and they are heavy. Panaracer Pro Tite tires are probably the lightest -- advertised at 270 g for folding 27 x 1 1/8. They look good too. My experience with Panaracer tires is that the sidewalls are somewhat fragile, but I don't have many miles on the Pro Tites that I have so can't say about them. They do give a "spritely" ride, though.