I'd love a critique on this one:

Feel free to use my name and website. 
EDIT:
Honestly my initial concept was just "Wouldn't riding a giant tortoise be AWESOME?"
But there are a number of directions I could have taken it. For example, I could have had the guy on him look incredibly bored or impatient and have other types of creatures streaking past. I think the concept I wanted to go for here beyond the initial COOL GIANT TORTOISE TRANSPORT thing was sort of "Joy in the Journey" (cliche as that sounds.) Rather than having your transportation be the sleekest, fastest, newest thing, why not have something that forces you to take your time? Why not get reading done while you're out running errands, when you can casually glance up between page turns to see if you need to steer in the next minute or two?
I hope I'm making sense, and that that even counts as a concept ;-). I'm looking forward to seeing the critiques, whatever images you choose.