Instead of having a scale of 1-10, why not use expressions like happy, confused, sad, angry, excited, dull, bored etc ?
What do you think would be the best way to display the emotions? A grid of emoticons?
A list/grid of emoticons would be fine for displaying the options. Nike+ does something similar to this when it gives you the option to say how you felt during a workout.
Why don't you just list them in a dropdown? I usually dont understand emoticons unless they have description etc. But thats just me :)
Nick has done a lot of research on this field and with early cstomers. If you don't know him already shoot me an email and I'll do an e-intro