Being a local tourist

[ultraviolet]

one of my favorite ways to spend a leisurely day with out-of-towners is to take a morning to ferry to bainbridge, then walk from the ferry dock to cafe nola on winslow way for brunch. wander back to the ferry dock and return to seattle. once off of the ferry in seattle, wander north along the touristy waterfront/pier area and visit the olympic sculpture garden. from there, you're close enough to walk to seattle center (where the science center, space needle and emp are located). or, just turn south and wander through belltown to pike place market. making sure to stop for random coffee and snacks as things catch your eye.

other than whatever you choose to spend on food, this is a fairly inexpensive way to spend a fun day. you only pay for the ferry one way, and the sculpture park is free...as is window shopping, people mocking and picture taking.

[NbyNW]

August is a great time to visit the Ballard Locks. With any luck, you'll see some fish, it's fun to see boats move through the locks, and it's free.

Any of the farmers markets can be fun, too -- Ballard and Fremont both have Sunday Street markets.

If your friend is in town for the first weekend of August there will still be some Seafair events, including fleet week and the Blue Angels.

[KnottedYet]

Rent a tandem kayak from Northwest Outdoor Center on south Lake Union and putter around the houseboats. The duckboat tour will take you past the houseboats, but a kayak will let you get right in there.
http://www.nwoc.com/

[Scrappy]

Go to Tacoma and see the Glass Art Museum. You can watch the artists live at work most days. Spectacular, right on the waterfront.

[smittykitty]

Pike Place Market, Monterail and Space Needle.

As you are also new to our area, I recommend day trips Ocean Shores or Long Beach (anywhere on the Pacific Ocean) or Mt. Rainier. Seriously, if you haven't been up to the Mtn. yet, you really need to go. Its incredible.

Enjoy.