What you're describing are tubulars:
http://sheldonbrown.com/tires.html#tubular

Tubeless tires are just like car tires. The wheel has a sealed inner rim so that no tube is needed. Racers like them for the reduced weight,MTBers and cross riders like them to be able to run lower pressures. I'd personally never use them,as I only commute,and punctures are much easier to deal with with tubes. Never had a pinch flat,as I'm pretty anal about checking my tire pressure.