How hard is it to do a topsy turvy cake? I plan on practicing first but have seen some really bad ones done. Any tips would be great. Going to see what youtube has to offer on this topic too...

This is a great demo.
http://forums.egullet.org/index.php?/topic/71115-demo-topsy-turvy-cake/page__pid__969488

Also Sharon Zambito's DVD is really good. I just tried one for the first time last weekend.
http://cakecentral.com/gallery/1947753

I used buttercream under the fondant and although I didn't have any problems I think next time I will use ganache so I can get some sharper angles. It's really not difficult I think the key to making them look right is to make sure your tiers are tall enough. I used three 2" cakes for each tier.

good luck!

I did my first one back in October and bought Sharon's video. I didnt own an agbay which she used but was able to figure it out without it. The only problem I had was making sure that I didnt cut too much out of the center to fit it right. But that was only because I lacked the supplies listed to achieve it. But as long as you have it all, its not hard.

Going to do my first one next week. Thanks for the tutorial links!