Put a class list (on cute paper, of course) in a picture frame. Use a dry-erase marker to mark students off of a list! Add a line at the top of the page to remind you what it is for. Field trip money, papers signed and returned, etc.
Number magnets to keep track of kids you allow to leave the room. Use a cookie sheet with glass stones glued to scrapbook paper and a magnet. then trim in fun duct tape! (The cookie sheet magnet board is pretty sweet for multiple different crafts.
Calming jar-tell child that they need a break and may come back when everything has settled to the bottom - I think I love this idea. Better than a simple time out for temper tantrums. some days I think that I need a calming jar.