Just opened up my new XL2 (from Zotz Digital), and found a promo sheet for this shiny bit of tchotchke:

http://www.cameratrack.com/index.php?cid=17

Reminds me of the E-Track:

http://www.bostoncamera.com/catgrpcont.html

(The E-Track was discontinued some time ago by its Swedish manufacturer. Boston Camera's rental unit is the only one I can find after a cursory search in the USA. I emailed the E-Track's European inventor in hopes he'd allow someone here to duplicate his design. It would solve a lot of dolly-space problems.)

The CameraTrack looks a tad pricey for a skateboard on a rail ... but the promo sheet offered a $100 discount.

JS

If it's a space saving dolly you need, you might want to check out the dolly in my book, Killer Camera Rigs That You Can Build. You can make several sized platforms and just move the wheel assembly to each platform. It can go large enough to stand on, to small enough to go through the window of a car: http://dvcamerarigs.com/backseatdollymovie.html

Dan
www.DVcameraRigs.com