Because I'm leaving the country and can't take with me everything I'd want to, I'm selling my favorite Ortlieb office bike bag (Compare: http://www.amazon.com/Ortlieb-QL2-Office-Bag-Black/dp/B0028FM97W/ref=sr_1_1?ie=UTF8&qid=1403755633&sr=8-1&keywords=ortlieb+office+bag).

Great for everything you need (and don't have to carry on your back anymore): with laptop insert, waterproof.

New almost 200USD, selling mine (half a year old, looks like new) for 120USD. You won't regret! They are just great!