I think a good widget would be a weight tracker widget. Enter your daily weight simply just by hitting your F12 button. Maybe show a start weight and goal weight and a graph showing the progress. What do you guys think?

PS: Is this in the right forum? If not can anyone tell me where I should post this? It seems like no one check the forums over at dashboardwidgets.com, so I decided to post here to see if I could get some feedback. Thanks!