Here’s a cool gadget—a ‘knee defender’, available from here: http://www.kneedefender.com/
You attach it to the arms of your fold-out tray table on an aircraft and it prevents the person in front of you reclining their seat, thus protecting your knees and your laptop’s screen/lid from suddenly shutting! Seems these devices are legal…
Thanks to Joe for showing me one of these and explaining its use.
Rhonda Bracey: At Random 
Too bad they don’t make something to get people to stop bouncing their legs up and down. 😉 I had the “pleasure” of flying from Vancouver to Toronto (that’s about a 4.5 hour flight) with a young man seated behind me who proceeded to bounce his leg up and down and up and down for 15-20 minutes at a stretch. As he was a tall young man, that meant that his knee was pretty much up against the back of my seat, and so my seat jiggled the entire time too. Thankfully he fell asleep somewhere over Saskatchewan. 😉
Or to stop kids from kicking the back of your seat! And when you politely ask the child to stop—even though you want to throttle it—the parent thinks you’re the devil incarnate. When I’m seated ready for take-off on a long haul flight (and everything’s long haul from Perth!) and see the family with two or three young kids just keep on walking down the aisle, I always breathe a sigh of relief… Try 15 hours with a child kicking your seat.
OK, I know it’s *nowhere* near as bad, but try being the parent of the completely clueless toddler who has no idea why their parents are dragging themaround the world, and why those flight attendants want her to sit down *now* … and she doesn’t want to, and she’s kicking the seat in front of her. I have been both appalled and almost wished the person in front would scold her – it might have more of an impression than a parent, because that’s the *first* person a child will ignore. Little varmints. 😉
Actually, I’m much more forgiving of the toddlers as they don’t know. It’s the 6 to 10 year olds that REALLY annoy me as they *should* know.