Update for south-bay area types (SF Bay, that is)
Stopped by Shaw's Lightweight Cycles tonight to see about a new wheelset.. This store is the real deal. Both mechanics(/owners?) were super knowledgable about track bikes and fixed gear, they had some sweet, sweet phil hubs on the shelf, tons of track bikes on the stands, and even an old 1-inch chain pitch hub on the countertop as a conversation piece (I guess). I don't know if I am going to get the wheels built there or from Harris online yet, but I'll definitely be back...
http://www.shawscycles.com/track.html
45 Washington Street
Santa Clara, CA 95050
408-246-7881