I really appreciate the effort I am seeing in the profile photos. You are really letting the creativity fly and expressing your personality. Your profile photo is important because it will be an image representation of you for all of your profile photos in your web applications (e.g. posterous, twitter, youtube, etc).
Since you have so many good photos, we will try and narrow down a profile photo as well as a self portrait photo, which should show at least half of your body (or full), which you need and will use later for a portfolio assignment.
Remember when you take your photos to use some of the photo rules you learned (rule of thirds, lines, camera angles, lighting, etc).
As you know, these profile photos are very small thumbnails so you need to take tight shots and crop them. Your face should fill in no more than 1/2 of the photo but no less than 1/4 of the photo. Look at David and Sharon's example and see the video below:
Basic Photo Editing
Some of your photos need to be edited. For example, many are dark and need to be lightened up a little (compare David's first photo with his second). A simple way to do this is to use the the free software version of Picasa. Google search "download Picasa" and install it for either your PC or Mac. Then experiment with the features (but don't get crazy with the effects). When you are finished editing your photo, click on the export button on the bottom tray of Picasa. Watch the video below to learn more about Picasa.
For David's photo above, I changed the following: brightness, contrast, saturation (more mellow colors), blur focus effect, and rotate.