TYNKYNs, Things You Never Knew You Needed: Sea animals like me find some human inventions difficult to take. One of our real dislikes is powerboats and jetskis. Not only do they make a terrible noise above and below water, pollute the sea and the air, they kill and injure many sea creatures. The poor manatees (dugongs) in the seas around Florida often have terrible gashes on their bodies made by the propellors of powerboats. Okay, we can understand that people need boats for some things. But what about jetskis? Who needs them? Answer: nobody. They're fun - toys really - for the people that have them. But everyone and everything else has to suffer the noise, dangerand pollution (don't forget they also need big vehicles and trailers to tow them to the beach) . Even innocent swimmers sometimes get killed or hurt by these silly playthings. And just listen to the noise they make above and below the waves (hold your breath and put your head underwater when one passes near!). What will people invent next for thrills? Oh yes, I know: space tourism.

You could have a go at making a list of all the things you know about which you can buy but which are of little or no use at all. Or you could try grading them on a uselessness chart like I have. You'll have different ideas I'm sure!

On the green side, put things that are useful or really useful, a longer bar for a more useful thing. Do the same on the red side for things that are silly, stupid, useless, big polluters, pointless or dangerous (like jetskis). You'll probably find that your friends have different ideas than you, but my guess is that you'll all agree about some things.