cup you insert that acts like a diaphragm to catch blood. cheaper than tampax and pads, less messy, no having to search for new ones, zero chance of TSS, etc, etc, etc... So a convert already.

http://www.mooncup.co.uk - they've been in use since the 30s, it's just that there was never as much incentive to market them like with tampax since you don't have to continually buy new ones.