Well, you wonder as per Wikpedia, how many bands out there really were influenced by the Urinals? I have never owned a CD by the Minutemen, but I have been aware of Mike Watt, their bass player for a few years. I know he's considered to be one of the great bass players in rock, or punk, or well, whatever category you want to slap on his output.
I rented a DVD about the Minutemen and it's one of those enlightening and inspiring little windows into a fairly obscure little subculture (Punk California Style?), with it's own roster of prophets, poets and madmen, and there are interesting interviews with people like Henry Rollins, Richard Hell, Jello Biafra, Lee Renaldo, and various ex-members of Black Flag.
It's a classic tale of outsiders, kids who had few prospects, but liked to hang out together and bash away on their instruments, making music that was crude but exciting. Over time they became quite adept at a certain approach, in fact, they finally became masters of their own wildly original genre of music. They broke all the rules, except, being true to their own do it yourself ethic.
D. Boon the lead singer and one of the principle song writers is one of the great oddball, eccentrics. He was a mammoth man armed with a sizzling Telecaster, and uncommon grace and wit. The movie is ultimately a love story of three guys who banded together to do their particular thing, damn the torpedoes...they blazed like a comet, and then, well, one of them met their demise, and the Minutemen were no more.