Hi, fiesta.cc is me - working on the white-labeling stuff as we speak. Shoot me an email if you think you might want to try it. mike [at] corp.fiesta.cc
he's offering any subdomain if you pay (e.g. lists.vrikhter.com), tweet @fiestacc
still fleshing that out, but will probably be free for smaller use cases. also, it's @fiesta :)