On the Get Satisfaction site (a customer support site) they have a neat little series of options when posting a comment. You can add notes on how you are feeling. As you can see in the screenshots below, you can choose a happy or sad face (or in between) and then you can choose a keyword to represent how you feel. Very nicely done.
Background: This is a puzzle that was first shown to me in the mid 1980s and ever since then I’ve shown to friends and family. It’s tricky, but given 10 minutes you should be able to figure it out. There are seven nails that balance on top of the 8th nail, and you cannot use glue or any other device to balance.