Just came back from the PGA show in Orlando. Did see some interesting products and one of them is the putter Wheel www.putterwheel.com. Have a look at their video.
Also was able to finally meet in person Mike Schy a PGA teaching professional in California. Mike has multiple GP putter with him. So if you are in is neighborhood please give him a call also have a look at Mike website at www.mikeschy.com. Mike believe in the Face-on-Putting method.