I don't know about anyone else, but, sometimes my days just fly by. It's often very difficult for me to keep up with what I'm doing and where I'm supposed to be.
My school has given me this really cool planner, but, it's 3/4'' thick and 4'' x 6''. It's small, but, I keep leaving it on my desk. So, enter The PocketMod... a pocket size planner you print, fold, and keep up with each week.
I really like to print a weekly calendar for each class period then add couple of pages of Simple List Organizers. You can throw one of these in your pocket with a small pen (I prefer the Cross Ion) and finally remember when someone asks you to come by and swap out an ink cartridge! :-D