Coconut cream powder for backpacking is quite useful :-) Both places you mention carry it. Hit Uji in Seattle though, not Bellevue, as the prices on the packets are 1/3rd of the price.
The Seattle shop carries a number of brands of it (it is next to the coconut milk).
You can use it instead of dry milk in oatmeal, rice dishes, etc. What it does boast is a power punch of fat (9 grams per serving). It gives trail curries, curry couscous dishes, etc a creamy and fatty texture.
I carry the Kara brand powder on my site (it is not Thai though, it is from Indonesia) and it is one of my best selling items. Whatever brand you get, get the packets in foil, and not the huge boxes. That way it doesn't go stale.
Now go make me some Drunken Noodles ;-)