I tried a messenger bag, I really did. My school store had a Tucano thing, i'm sure it wasn't high quality, but the style just doesn't work for me. It really hurt my back and made it hard to ride my bike. But I still don't feel comfertable just putting the MBP (albeit in a neoprene sleeve) in my regular backpack. I feel like the shape of the bag is causing the MBP to have pressure put against its middle. So I'm looking for a MBP (15") backpack at around $50 or so. I can go higher, but I'd like to keep it as low as possible. Any suggestions?