I've got Velosurance. It seems relatively expensive. I pay $33/month (~$400/year) for $3,500 in coverage. I'm happy with it but I am hoping to see prices go down some day. Perhaps if more people insure their bikes and Velosurance gets some more competition in the marketplace, prices will drop, but that's just wishful thinking right now.
Thanks Cameron... I wrote to both Spoke and Veloinsurance and have yet to hear back from Spoke. Veloinsurance was, and is, extremely responsive. I signed up with them.