As a new owner of an LS twisty (thanks Phil B!!), I love the form factor, but the battery rattle was annoying, nothing functional - just annoying. I've tried the Dr. Scholl's foam pad on my HAIII Ultra-G and it works, but it quickly starts picking up dirt/oil/oxides from the threads. I also had some concerns about it losing its resiliancy over time, and the potential for glue gunk when it was replacement time. I went to Home Depot and, after some trial and error, found an o-ring that just fit over the diameter of the bottom post, and stuck up just enough to keep the battery from rattling, but would give when compressed. From this thread it looks like there are several different twisty's out there, but mine took a 3/8 x 1/4 x 1/16 o-ring (#5). When it loses compression, you can just pop it out and replace it with another.