This is just a quick shout-out to you early adopters that, as of the August 22, 2012 nightly build of Firefox for Android, support for Explore By Touch, Jelly Bean style, has landed and is now working. If you use a Nexus 7 or other device that already has Android 4.1 Jelly Bean, you can explore content by dragging your finger, or go sequentially by using the swipe left and right gestures. Activate an item by first setting accessibility focus to it via one of the two means described, and then perform a double-tap anywhere on the screen.
You can get the newest version of the Firefox nightly build either through Software Update (Menu, Settings, About Nightly, Check for Updates link), or by visiting the Nightly builds download page and downloading the standard Android build from there. You will probably not want the ARM V6 build, since that is for devices with that older processor running Android 2.3 or earlier.
Have fun, and feel free to leave us feedback as usual!