I assume I can do this? See examples on the very top of my main website, or my phpbb forum. I'm relatively proficient with ftp, and finding the files I need to alter. If the banner has to be made wider to do this, I'd probably need advice on how to do that too.
Oh, this is my new wordpress blog using radiate.
By the way, I found a similar topic, feel free to delete if you like. :-)