Soda Tracker is a very compact program that can be used to keep track of the soda you've taken from the fridge at work. It will keep a log of transaction type, transaction date and time, the transaction amount and your ending balance that can easily be displayed at any time. It starts minimized, so unless you tell it to show the main window you will never be bothered by it. You can just start it and keep it running and perform all the main functions all from the tray icon.
||Windows XP/2003 Server/Vista, Microsoft .Net Framework 2