Brew cycle is fun but a bit spendy
There are Portland walking tours, but I haven't been on one
Good Portland hikes sub-1hr:
Forest Park, you can go from McLeay park to the stone house and back out
Multnomah Falls, you can hike to the top
Fairy falls
http://www.oregonhikers.org/field_guide/Fairy_Falls_HikeGood coastal hikes sub-1hr:
Haceta Head lighthouse and tour
Cape Perpetua- go see Devil's Churn and the tide pools
Ecola State Park has some
Amazing waterfalls but 2.5 miles:
Punchbowl falls in the columbia river gorge
Seafood:
I don't eat much of this, so I don't know Portland rec's personally, but I hear good things about Jake's Crawfish and Salty's
Coast: Mo's is well loved, but some people like to be critical of it. Certainly long lines a lot of the time.
Eugene: Newman's fish market does really good fish and chips
Other activities:
You can go stand up paddleboarding near Ross Island in Portland. So much fun for the price. Really easy to learn even if you've never done it. They also do kayak rentals. Portland Kayak Company.
Right by there is a McMenamin's and a place called Buffalo Gap, which has more of a hole in the wall feel. Either place you can get a good burger and a beer. Buffalo Gap does some incredible breakfasts, actually. Good hollandaise sauce.
While you're down at the SE waterfront, I recommend taking the OHSU tram and seeing the views of the city. You can also take transit across Tillikum crossing and go to OMSI, which sometimes has some incredible exhibits. Not sure what's there right now.