If you have an iPad2, take a look at this from inCase:
Lounge Case. I got it when I got my mom her iPad and she really likes it. It's got little beads in it so it'll mold to your legs/lap. Very nice, actually.
On the inCase web site, they've got it listed at $59.99 (USD), but I've seen it elsewhere for $49.99. Just do some Googling...
Oh, and if you go to the Best Buy website, some guy has done a video review of it, so you can "see it in action." TBH, I'm kind of jealous that my mom has it and that I can't get it for the classic iPad (I wrote the company, they have zero plans to develop one for the iPad1).
Hope this helps.
Marilyn