Just like how there is an "Add to Favorites" button on practically all objects, I would love to see Tasks, Projects, and Issues have an "Add to Timesheet" button. The timesheet search is too cumbersome and is a deterrent for everyday use. We have a lot of tasks and projects in the system and many are late, or outside of the timesheet timeline so being able to easily identify a task you need to log time to and add it to the timesheet from that object would be an easy thing to teach users.
