I was looking at those in the store and I decided to get some that I saw on Petco's website (but ended up ordering them from amazon, since they were only $33 on there) because they fold up. I'm supposed to get them tomorrow (I ordered them Monday, so that's not too bad for free shipping!) so I'll let you know how they are.
Amazon.com: Solvit PupSTEP Plus Pet Stairs:...