I'd like to give you lots of info about the Belmont street fair as this is my neighborhood. Unfortunately, the business 
association page is rather lacking and all I have is below (They have a TROLLY!) Still, you should go.
You might see me as I try to hit 10 events in one day and document them all. If you have info about what will happen there…please add away in the comments
Related: 75+ Portland Weekend Events, Parties & Free Tickets | September 10-13
Saturday, Sept. 12, 2009
10:00am – 5:00pm
Vendors, Live Music, Sidewalk Sales, Entertainment
Free Trolly
I was at Belmont Yoga last night, and the owner said this was going to be pretty big – over 100 booths along Belmont, and a trolley to take people East of 39th.
Two businesses in her building (between 42nd & 44th) will be having somewhat of a grand opening – their spaces are not finished yet – one is a chocolatier and the other a breakfast place.
She said the breakfast place would have tables out front where you make your own pancakes – they bring you different flavors of batter and you go to town!
unlike the Hawthorne street fair, the Belmont actually shuts the street down to automobiles…at least they did last year.
it was fun!