RockyMounts, based in Boulder, Colorado, has been making bike and ski mounts that fit Yakima, Thule and other roof racks for years. They offer the same quality as the two big names, but at a lower price point and with a vast array of colors. 
New for 2011, RockyMounts has introduced the DriveShaft, which is not a complete bike mount, but rather an adaptor to fit bikes with 15mm and 20mm thru axles to the standard 9mm bike mount. They are not the first to introduce this type of mount, but the RockyMounts model offers a level of security that the others do not.
To use the DriveShaft, the rider must remove the front wheel from the bike and tight the axle back onto the fork. The DriveShaft mount is clamped to the existing bike tray mount using the 9mm quick release just like a standard bike fork would be mounted. The wide mouth, cam-adjusted mount is opened, the bike is mounted to the roof rack while inserting the axle into the wide mouth opening and the cam lever is closed. Once properly tightened and closed, the high-friction rubber pads inside the opening prevents the axle from being unscrewed. Each DriveShaft comes with a lock and two keys; but remember that if the DriveShaft is not locked to the 9mm part of the rack, a thief can still walk off with your bike.
The DriveShaft also comes with an adaptor to transform the mount to a bolt-on configuration if you have a bed mounted type of setup. The DriveShaft will be available in black during the first quarter of 2011 and retail for $64.95. Rock on!