I started doing this last year and it has worked wonders. I got the idea from a friend, but she got the original idea from the fabulous blog- The First Grade Parade. It's called a Bravo Board. I like to use a dry erase board for simplicity. It happened to be a magnetic dry erase board, so it made attaching the colors and title super easy!
All my desks are arranged in groups of 4-5 per group. Each group of
students gets a colored bin containing supplies. Whichever color they
are designated is the color for their group. They learn to work as a
team and have to earn tallies as a team. This was also a simple way to
teach tallies, and trust me by the end of the first 6 weeks all of my
students knew how to use tallies without any problems. At the end of
the week, the group with the most tallies get their names put in a
drawing for a free homework pass and they get to become the BRAVO table
for the entire next week. I have a little cone that says Bravo that I
place at their tables for the week. They honestly all work really hard
to be the Bravo table!