I just use a shallow ceramic dish. It's designed for plant pots to go on outdoors but it's perfect for us.
Bit like this...
http://www.diy.com/diy/jsp/bq/nav.j...refview=search&ts=1286836771630&isSearch=true
Only ours is terracotta and we got it from a garden centre. It's a perfect size for veggies for a pair and gives them space to have two piles of pellets to reduce chasing at meal times.
I use a shallow ceramic dish. Basil still throws it about though.