I stumbled across this great site: http://www.knitmap.com/. It allows people to add, review and rate yarn shops in their area.

It looks like a great tool for planning a trip anyway, but it also has an actual yarn crawl feature. You can use this to plan, map, and print your way through all of the yarn shops your heart desires.

I wonder if all 19 of the Portland yarn shops are really there.

So get on there and add/review/rate your local yarn shop!