Many classes are now using Twitter - I know mine is: www.twitter.com/mrfeistsclass. As such, a lot of my children like to leave a Twitter exit ticket to show their learning that I can then turn into a Tweet at the end of the day. At the very least, these engaging exit tickets allow the children a few minutes to reflect on their learning for the lesson.
To save silly amounts of photocopying/printing, however, I do laminate one or two of these for each child, so that they can use a whiteboard pen to jot down their learning. On the back, I have attached a small velcro pad, so the children can stick it to the display on the back of the door as they leave - then, they wipe it clean the next morning/lesson and begin again. I have been tempted in the past to stick a laminated one to each of the children's tables instead of the door sticking - however, they do seem to like putting up their ticket each day!
I hope you find this resource useful.