We have gherkins here in the US. We love them! My daughter was asking for gherkins and capers at the age of 2 ("more crapers please!").My personal, safe'ish, favourites are making a light bulb glow by popping it in a glass of water and the glowing gherkins (pickle in the US I guess) which I seem to remember can be made more impressive by sticking a pencil lead in it.