ReBecca at Dinochick Blogs has already pointed this one out, but being a consummate trilobite lover, I just had to pass this on to anyone who might have missed her excellent post.
Besides being able to purchase a neat, colorful trilobite - for play, for teaching, or for decorating one's house or improving upon one's otherwise dull-looking collection of rocks and minerals - you can get a collection that includes replicas of 500 million-year-old animals of the Burgess Shale from the Royal Ontario Museum online. (The trilobite comes with the collection - see ReBecca's photos replete with scale bars, like this one, or go to the ROM webpage directly for your purchase.)
Trilobite for sale or rent
Olenoides makes a nice present.
Burgess Shale toys all around,
That's as much as I will propound...