If you like books and you're in Portland, don't miss Powells. And if you like technical books (eg. computer stuff) don't miss their technical book store a few blocks away.
The technical store even has a display of old computer hardware - an Apple II, an Osborne, an original Mac, etc. I can remember quite clearly when those machines were the hot new thing. That's dating myself, but there's something to be said for perspective.
One of the nice things about Powells is that they mix new and used books. That means you see older books and books that are out of print. They had several copies of Software Tools by Kernighan and Plauger. I remember how excited I was about that book. It came out in 1976, when I was 16. A few years later, a friend and I wrote versions of some of those tools (in C, compiled with Whitesmiths compiler) and sold them. Not that we made any money at it.
That's the exception though. Most computer books don't age very well. They become useless a few years after they're published. I should know, I have piles of them!
Between the two Powells stores, and a Borders I visited on the way there, and between computer, science, environment, and science fiction, I made note (on Evernote) of 30 books I wanted to read. I didn't buy any, which in a way was easier - it would have been tough to choose! (I've already bought one on my Kindle).
Oh well, I guess there's worse things to be addicted to!