Add a picture to your profile!
Click the User CP link at the top of the page to upload a headshot. Then from the links at the left, select edit profile picture, and edit signature.
Currently it allows a thumbnail of max 100px height and width.
For the picture to show up in your posts, you need to click the Edit Avatar link in the UserCP. Here you can upload an image of max 100px as well.
Let us all see your happy face.