This was posted on another forum I go to and thought some here might like it as well.
You put in your height and inseam, select the type of bike you want to evaluate and it shows how you would fit, both with your feet up on the pegs/boards and on the ground. You can even modify the stock seat, bars, and pegs as well.
Another kool feature is you can add several (I did 12 before I stopped) bikes at once. Then you can roll your mouse to move between bikes so you can compare how your position changes from one bike to another. Not quite the same as taking it for a spin but it gives you an idea how you might feel on different bikes.