The first tool I can't live without is a Door Blok. From Rick's website: "I created DOOR BLOK back in 1988 after attending a study on classroom distractions. The presenter pointed out that the #1 distraction in the classroom was the sound of the door opening and closing. From the rattling of the knob or handle to the clunking of the door as it closed, these annoying sounds are heard a hundred times a day. DOOR BLOK makes it easy for students to enter or exit your room. Since the latch is not engaged, a simple push on the door will open it. The closing sound is muffled by the cushioning provided by DOOR BLOK's heavy-duty SBR."
It is truly an amazing tool! It hangs on the inside of my door when I lock up my room, so it never gets lost.
The second tool, also by Rick Morris, is a binder stand. It's a simple plastic piece that clips to the sides of a 3-ring binder, turning it into displays for centers, directions for games.
I have several clips, including using one to stand up my weekly lesson plans, so it doesn't get buried under piles of paper on my desk!