Jakartha,
I am the main culprit responsible for banners and Avatars but I've taken my eye off the ball lately as there are several people already waiting for banners. I tend to get creative bursts, so if you stick around you'll just find a personal message with your own personal banner and avatar included appear one day out of the blue.
If any of the other graphic artists on the forum would like to take a shot then by all means be my guest. The standard banner size for the site is 580 x 67. I recommend working on an image 4 times that resolution then flattening it before reducing it to the forum size, that way you'll keep all of the detail...
Jules