It'd be cool to have a DateTime picker. Just off the top of my head, it could be similar to the Date picker, but maybe display three months side-by-side so that it'd be a wider control. The greater width would be needed because below the calendars, you'd have a slider with 00:00:00 to 23:59:59. So you'd pick the date, then "slide" the time and you'd be good to go. With 1440 minutes in a day, perhaps it'd need to only allow 15 minute increments, which would be fine for many uses. Or maybe two sliders - top slider for the hour, bottom slider for the minutes? I think it'd be a convenient control for many applications.