Story lines is a fun app for developing stories as a team. It follows the same pattern as the game of telephone. One student begins with a phrase and the next student draw the picture. It follows with other students adding on to the story without knowing the original phrase.
Several tips from John Van de Walle about teaching measurement. I have his book from one of my undergraduate methods courses for teaching math, and I LOVE it! He's got some stuff for teaching math hands on and recognizing patterns!
Free Online Graph Paper / Grid Paper PDFs Downloadable and very printable, I find these PDFs extremely useful. You can tailor it to your own needs, change the size of the grids and use different patterns such as hexagonal, octagonal, and circular graphs.