I've got to admit, the distinction between leggings and tights has always been lost on me.  But if wearing tights with no pants is indecent, then I can understand why Errol Flynn had such brio when playing Robin Hood.

A quick Google search later and the answer is: no sir -- leggings aren't pants.  I don't care if they're indecent, it just ain't a good look.

I'll do a qualified yes, but only on women and only if they don't require their own zip code.

I'm with Bill, on the right women it works.  Never for men though.  

I'm all for letting people wear what they like...even spandex...especially by those who shouldn't.  It provides a part of life's amusement.