if you click on my mibba, and then click css down along the side there will be a link to some pre made layouts that you can look at pick from.
also you could go to the forums. there is a profiles forum:
http://www.mibba.com/forums/view/Mibba/Profiles/
there you can request a layout and someone will make you one, or you can go into the topic where people share layouts theyve made.
aaaand if you google mibba layouts you can find some sites where people make layouts for others to use :)