Today is a great day for beer drinkers. There is a plethora of events going on. Widmer Brothers, and Fanno Creek are both having Oktoberfest celebrations. Also tonight, the Portland Art Museum is hosting an event featuring Laurelwood, Lompoc, and Lucky Lab. I do not know much about the details for that one, and PAM doesn't list it anywhere I could find on their site. (update: it is actually on the 19th, the date was listed wrong on SNOBs site.)
Also, if you feel like going out of town, there is a Septembeerfest going on down in Corvallis. It sounds pretty cool, and features a pretty good lineup of brews. I am not up to the drive, as I am going to Medford in a few days, and tend to limit my I-5 travels to a bare minimum. If you go, make sure to check out Calapooia in Albany, they have 4 or 5 dart boards, and take darts pretty seriously there.