I've bought some "cel books" from Michaels.  
They're a little more expensive, but I actually 
REALLY like them a lot more then the Itoya 
artbooks. 

The ones I get are "Family Treasures Deluxe, EZ 
Load memory books"  They come in 2 sizes - 12x12 
(good for cels without backgrounds, or trimmed 
backgrounds) and 12x15, which will hold most 
cels with backgrounds and slightly oversized 
cels. These are a LOT sturdier then Itoya's 
books and I keep them on a shelf (*cough* err, 
actually shelves.. heh) on my bookcase. :)

12x12 are 14.99 and the 12x15 is 21.99 (at least 
where I'm at - north TX)  Oh, and they're 
located in the scrapbook / memory book area. :)

They *are* clearly labeled archival _and_ acid 
free, so they're safe. :)  

Look in the Sunday paper though - Michael's 
almost ALWAYS has a 40% off coupon, so it makes 
them very reasonably priced when you buy them 
that way. =)

Good luck! 

Sheri