MacLocks just added what it calls “The First iPad Security Cable Lock”, the iPad Lock - a clear plastic iPad case that can be closed with a lock (same locking mechanism as a bike lock) and tethered to whatever your heart desires with a coated steel cable. In Apple-fashion, “This makes the iPad Lock flexible and light, not to mention stylish, so you can easily pack it in your bag and take it with you wherever you go!” Once it’s secured, the only way to remove your iPad is with a key. The case itself is $39.95, or you can purchase the bundle (case & lock) from MacLocks for $64.95.
Is this a little too much for iPad protection - probably. If someone really wants your iPad, they’ll find a way, but this will certainly help you feel (over) secure.