So I am looking to buy some accessories for my Trek DS. Currently I ride a very stock Dual Sport with Ergon GP2 Grips. I am looking to add some other features to it, but don't know what are the necessities to have with the bike. I am assuming a hand pump, spare tubes, etc....but there is just so much stuff out there that I do not want to be buying items that I will never use. What are the must haves that you take with you on your hybrid, and what do you like to take them in?