Minglement, a store on Vashon Island, sells some great loose leaf tea. My best friend gave me a packet of their New Moon tea, my favorite kind, for Christmas and I've been enjoying it so much.
I need to get a loose leaf tea infuser, but for now I've been using a travel mug with a built in strainer, similar to this one and this one. In mine the tea is put into the infuser and you can raise or lower the infuser when you want to steep it.
There are also a lot of cute options for infusers for cups or tea pots, like this leaf one, this hippo one, or this cat one. I've also seen a manatee tea infuser, and a ship tea infuser.They also make simple metal infusers, or you could also use a coffee filter if you needed.
(Update 1/23/2016: I bought the manatee infuser but I'll be returning it. The holes aren't fine enough and I have tea leaves in my tea. So I'm going to look for a metal infuser.)
Are there any places in the PNW you like to get loose leaf tea?