Playing with pebbles

... on a very windy (but sunny) day.

My first is in plank and also in stick,
My second's in slim and also in thick,
My third is in tea and also in pot,
My fourth is in note but never in not,
My whole is a toy to play with outside
As, when the wind blows, it will go for a ride.

Riddle © Celia Warren 2012

If you enjoyed that riddle, have a go at this one on my website.

Slightly worrying: can you see the sort of out-of-focus splurge, top left? There seems to be a mark on the inside of my lens - looks as if it could be condensation. What on earth can I do about that? It's a Canon Powershot SX210 IS. Any advice gratefully received.