If the iPad is stolen, you can make sure the data is still safe by routinely backing up, and you can ensure the iPad becomes unusable. What you cannot do is use any technology to recover the hardware. Any thief with any knowledge at all will be able to make the iPad invisible to the world in less than five minutes.
Common sense usually prevails: don't wave it about in public, and certainly never let go of it. Would you leave a few hundred dollars sitting on a table while you drank a coffee and chatted to a friend? Make sure she doesn't do it with her iPad!
It won't prevent you iDevice from being lost or stolen, but may aid in getting it returnened if lost. I put one of the return mail stickers (name, address) on the rear of my iPad, iPhone, and laptop.
That way an "honest" finder would be able to contact me.
Also, record your iDevice's serial number and keep a copy of the sales receipt.