I setup an online practice tree for those interested in practicing while in front of a computer. It isn't necessarily made for practicing with electronics (no delay box option) and obviously there is no pedal for us foot-brake racers (just a mouse), but to get your eyes and mind used to seeing the tree and the lights - I think it is okay.
http://www.dragtracker.com/practice-tree/
Let me know if you have any feedback for it - I haven't had too much activity on it since I launched in late January, but I'm open to suggestions.
Thanks!