As a player, I bought one of those little white boards (about the size of a sheet of paper, the kind that students put on their dorm room door), and it's been very helpful. I mostly use it to keep track of initiative, but I also keep track of hit points, healing surges, action points, magic item dailies, status effects, etc. It sure beats using a pencil and erasing every time you need to change something, and it's way easier to erase than my Chessex megamat. It's also very portable. I bought it in the off chance that it'd be helpful, and I'm glad I did.