crowwe:
Can I change my profile picture?
Yes.
Go to My Profile (yours, lol), click on Appearance, in the pop-up, avatar selection is on right. On left, for photo you can browse thru your own photos, pick what you want, and upload it.
Once you're done, and saved the new photo, you'll need to refresh WGT to 'pick up' the new image. There is probably a size limit; you can always crop or resize the photo first to get down to about 100 x 100 pixel size.