As shown on the Bulbapedia page for "Pokémon Dollar", there are bunches of different names people give to the P with the two crosses.
And given the nature of Colosseum and XD, I don't think they can really be counted as official names that apply elsewhere, simply because you never actually see them elsewhere.
So I'm just interested, Pokémon fans. What do you call it?
I'll start with a vote for "pyen", 'cause that's what I call it.