When we were both at a meeting, my CT secretly had our sub (the librarian) do an acrostic about me. Later, my teacher sent me out of the room (the other 2nd grade class "borrowed" me for a while) and had the kids make up a book. They each did a page of "I liked ____. I learned ___" etc. and illustrated it. She included some pictures, laminated the cover, and bound it in the comb binding machine. It made me cry.
That was from the kids... she gave me a couple of teacher-themed notepads (I did a farm unit, so she got me a couple of farm-themed ones, and a generic bus one), some post-it notes, some blu-tack (because that was a big thing with us!), and a couple of her favorite books that can be used with ANY level (Kevin Henkes was the "favorite author" at the moment, so she got me several of his books). The room mom also came with flowers and a notepad with the school's picture on it. It was really sweet. I still have that book and go back to it.
She also took TONS of pictures of me, of the kids, of me with the kids, and of our projects and bulletin boards and whatnot... and on the last day, she gave me copies of ALL of them. They came in SO handy for my portfolio!!!
The other 2nd grade teacher gave me a gift certificate to the teacher store. You can never get enough of those!