2001-12-31 123.4 12.3
Where the space-seperated fields are date, weight, and body-fat percentage. It loads up this data from a file ("fat.txt" in the same directory as this html page) and creates two graphs, with a timespan selectable by the buttons at the top.
This probably only works with recent Gecko browsers (Firefox, etc.) and Safari, because the Flot plotting library relies on <canvas>.
Download fat.html, fat.js, jquery.yui.js, jquery.flot.yui.js, and place them in the same directory on a web server as a file named "fat.txt" with samples, one per line in the format described above.