I felt a bit adventurous today and decided to take my cheapo Ebay case and make it into a Smart cover with a magnet. Details are on my blog and I made a video. All you need is a knife, earth magnet and glue.
http://www.youtube.com/watch?v=_QhWdQRku0o
http://www.youtube.com/watch?v=_QhWdQRku0o