Hey! Hope some of these work for you:
1) Have the students write one good thing about all the others and type a list for each student. I'm sure you've heard that story before.
2) Make class T-shirts with the handprints of all students (teacher too if you like). We have a first grade teacher who does this every year.
3) There's a post on here somewhere that talks about making a DVD for the class. If you can find that, you might get some good ideas there.
4) You could make some kind of picture frame and put a class picture in it. If there was a mat, everyone could sign it too.
5) I still have a glass my 4th grade teacher gave us at the end of the year. It was a clear, tall glass and she painted a small picture, our name and the year on it.
Enjoy the rest of your year!
GG