Was looking for a 100x100mm wooden gatepost yesterday, and ended up buying something called a Decking Pergola Post (because it had a smooth finish with rounded edges, and it was cheaper).
This was only 90x90mm, but it still seemed quite light, and the guy in B&Q managed to cut off one end with a handsaw in about half a minute.
Is there something special about these posts (like the sort of wood they use), or will it do the job (as a gatepost) just as effectively?