I meet a lot of teachers in FE who shy away from group work because of the carrolling and shepherding that's needed.  In some lessons it's just blimmin' hard work and there's not enough time, right?  You've got a MOUNTAIN of stuff to do and it's better if everyone just gets on with it.  But research has shown conclusively that group work in class significantly raises co-operation, increases engagement and improves learning.  So what does that have to do with Egg Timers....?

If you have time constraints, use whatever it takes to keep on track.  Each working group could have their own egg timer on the table.  Nominate a time keeper for each group.  When there's only 5 minutes left for the activity to be completed, the nominated time keeper turns over the egg timer and counts down.

Another use for an egg timer is to have times for absolute quiet in the class.  This is particularly useful if you have students with a tendency to call out during questioning.  The egg timer offers a specific goal - totally measurable - for the student to keep schtum.

And finally, if you get yourself a series of egg timers with differing times (I have 3, 4, 5, 6, 7 + 8 minutes) they can be useful tools to stretch concentration and focus for students who have problems with this.

At first some students might sit and gaze at the sand as it's pouring through the channel from top to bottom, but they'll soon get over it.