Glenn Randle is a glassblower and his North Carolina-based studio, Fire Dancers Glass, makes some of the most beautiful vessel sinks I've ever seen. Glass vessel sinks are not difficult to come by, but I can tell you that I've never seen colors this saturated and rich in a vessel sink before.
His sinks are functional art glass, there's no better description.
His "standard" size is between 15 and 16" diameter and between 5" and 7" deep. The sinks are drilled for a standard 1-3/4" drain and their bases are machined to a 4" diameter to allow for a stable installation. He offers a lifetime warranty on his sinks and he'll also make custom sizes and colors, all you have to do is ask him.
Fire Dancers Glass, the website, is also his catalog and you can see his current collection there.
Glenn also makes what he calls Ribbon Vases, speaking of art glass. The depth and organic feel he achieves with these vases is remarkable.
Here's close up of the side of a Ribbon Vase. Gorgeous stuff Glenn, just gorgeous.