Hey there, I actually used to work in Silverdale and in Port Orchard, so I took the ferry every day for awhile and drove through BI quite a bit. I live in Seattle now.
Bainbridge Island is in Kitsap County across Puget Sound from Seattle. There's a lot of contention (or there used to be) about how fasts the ferries are allowed to cross the water (something about disturbing aquatic plants and wildlife), but it takes between 40 minutes and an hour each way. It's also quite expensive to take the ferry: I think the auto ferry has gone up to $10 each way. The passenger-only ferry is much cheaper, but then, of course, you've got to either have a bike or catch public transit on each side. Still, if you're going to have to commute every day there and back, it really makes a lot more sense to live on the side you work on unless you're making a ton of money and can afford to drop a couple hundred a month on ferry fare.
Housing in Kitsap County as a whole is cheaper than it is in King County (where Seattle is), but I think among the cities in Kitsap County, Bainbridge Island is one of the most expensive. It's very cute and quaint and definitely capitalizes on its artsy, cozy harbor feel, but it drives the cost of housing up. There's a ferry that runs from Seattle to Bainbridge Island. There are cities just on the other side of a little bridge, like Kingston, that are definitely less expensive. Farther down Highway 305 (I think) is Silverdale, which is an unincorporated town that's actually pretty decent sized with a mall, several strip mall developments, schools, restaurants, bars, etc. Farther down is Bremerton, which used to be a pretty busy city with a naval shipyard, but now it's kind of a gritty, dirty, tired town with a pared-down shipyard. It's definitely the closest thing to city living in Kitsap County, but it can be a little rough in some areas. There are apartments there and they are affordable, and there are also cute areas of town. There's no mall (the one in Silverdale killed off the economic activity in Bremerton), but there are restaurants and bars and clubs, schools, social service agencies, lots of churches and daycares and offices and whatnot. There's a Seattle to Bremerton ferry. A little farther down is Gorst -- it's a shithole, don't live there -- followed by Port Orchard, which is also a cute little town (in some places) and is the county seat. Port Orchard has an historic downtown with old wood buildings and a nautical theme, and you can also catch a ferry there that connects to West Seattle (which is nowhere near downtown Seattle; West Seattle is a whole different section of town.) Housing there is definitely more affordable, though apartments aren't in as good supply.
From all the people I've known who lived out there, it's not terribly difficult to take the ferry over to Seattle in the evenings (I think the last run is somewhere around midnight) and on the weekends for hanging out or whatever. Most of the people I met over there were nice, if not somewhat quirky, and most wanted to live there because of the natural beauty and space. There are some nuts there, though, who are all about that rural, militia-type, government-off-your-back thing, and there have been some grumblings about white supremacy activity, though there's a very active human rights network that does tremendous work over there. I remember talking to a comic book artist who had moved with his wife and baby son to Port Orchard, and he said several artists he knew were moving there because it's so much less expensive than living in Seattle. I don't know if there was any sort of exodus from Seattle to Kitsap County for cheaper living, particularly for artists/creative types, but he definitely had a point.
Anyway, this was probably far more information than you wanted, or than should be posted on a message board. :) If you have more questions or want help finding more information, just drop me an email at IsavdLatn@hotmail.com. I'd be happy to help.