In the lesson linked below, students are given play-doh and a candle and asked to time and then graph the time it takes for the candle to burn out by taking measurements every thirty seconds. Obviously this lesson is a bit of risk considering fire is involved, but can be an excellent lesson if facilitated properly. Applications include x-intercepts, y-intercepts, slope, slope-intercept form, domain, and range.
Lesson guidelines: http://auhsdmath.pbworks.com/w/file/fetch/60112716/Day1_TD_Linear%20C%281%29.pdf
Handout: http://auhsdmath.pbworks.com/w/file/fetch/60112715/1.1_BurnBabyBurn%281%29.pdf