Everything SeeBass said.
The bar at the Hotel Deluxe (the Driftwood Room) is probably my favorite bar in town. The Ace is good if you're into hipsters, but I've heard the beds are not comfortable (futons? really?). The Jupiter Hotel if you're really into the rock and roll lifestyle, but be prepared for lots of crowd noise at night from the attached club. Or, as BigBrodieFan mentioned and if you're into funky and eclectic, there's the McMenamin's Kennedy School or their new Crystal Hotel that just opened downtown. The food and booze at all the McMenamin's places (and there's A LOT of them) is just passable, though.
There's a never-ending supply of good restaurants in town, in pretty much every neighborhood. I'd be happy to point you to restaurants if there's something in particular that you like to eat, or if you know what neighborhood you'll be staying in. Lots of excellent restaurants that use only local ingredients, and of course our world-famous breweries and
distilleries (and wineries a few miles south and east). You pretty much can't go wrong with any of the brewpubs, but the bigger ones (Rogue, Bridgeport, Deschutes) are very crowded and touristy. If you are anything of a beer nerd the industrial east side is the place to go, not the Pearl district north of downtown. (again, let me know if you want some more specific recommendations)
Of course
Powell's Books - still Portland's #1 destination. And speaking of shopping - there's no sales tax here, so some things do tend to be a bit cheaper. Besides the Adidas and Nike outlets, there's also the Columbia Sportswear outlet. I'm not much of a shopper, so I'm probably not the best source for tips in that area.
Unless you plan on getting out to the Columbia Gorge, Mt. Hood, the Coast, or the Willamette Valley (where the wine is) you shouldn't need to have a car to get around. Our
public transit is very good, goes just about everywhere and is easy to use. Biking is also a good way to get around, there's a lot of bike paths and most of the major streets have bike lanes. Also a very pedestrian-friendly town.
I love to point visitors to some of the more off-the-beaten-track things to do here that aren't necessarily going to be in the travel guides, so if there's anything you're curious about, don't hesitate to PM me.