I transport my iLiad in the "deluxe cover"
http://www.justread.de/shop/product_...vhs5ibkus3q535
It is protected rather well from shocks. I transport it daily together with my subnotebook in my backpack also stuffed with books, dancing shoes or whatever the day calls for and had no problems so far.
It has beein said altough, the iLiad screen to be quite fragile to "twisting pressure".. I never dared to try out what happens if I take it at the ends with both hands and twist it, so to have the insight: "Oh yes, it indeed breaks if you do this"...
Interesting enough in both cases I read about sudden display crack, it was always the provided shoulderbag people give a good iLiad in and took a defective out... hmmm.. (the third case I read about here was a someone who droped his cellphone onto the iLiad screen...)