If only we could convey our moods more easily in the workplace. Well now you can, no need to pussyfoot around, you already know what sort of response you're likely to get by the sign on their desk.
The Daily Mood is a bit like a mini flip chart, just peruse one of the 47 moods on the chart and leave it on the one that best dictates the mood you're in. There are 47 moods to choose from, each with its own smiley/emiticon. On the back is a brief description of what being in that mood might entail, although you probably already know this.