My Mom, daughter and possibly my granddaughter are teaming up to lose weight in 2008. We've setup a Google spreadsheet to track our progress, listed our current weights and committed to a goal for the year. Our plan is to check in with each other weekly and look at our week's loss at that point. Then support one another in any way we can.
The reward... besides increased family communication and fun... we plan to do a spa day at the end if we meet our accumulated goal. Definitely a win-win!