Everwears, if you don't mind a crapload of rotational mass. I've been skidding one like crazy for nearly a month and a half and it looks like they have like 2 more months to go.

I would never run one up front though.

P.S. I think Soma says something about them essentially being for the skidding fixie rider. 5mm thick tread.

****ty sidewalls though, and as the tread thins I suppose punctures will become an issue.