It would be really useful for a cell phone engineer to comment on this forum for all zip codes. I'm not one of those, but I'll suggest some points for an expert to elaborate on. The Everett-Seattle-Tacoma-Olympic Peninsula area is very poor for this technology even though its creator is from here. In the simplest case of one tower and one phone, tower antenna radiation propagates radially like a disc from the tower. Along the way, signal strength to cellphone receivers undergoes physical attenuation due to spreading, refraction, and atmospheric absorption in direct line of sight. There is additional absorption and reflection to the point of blocking due to intervening materials. When a tower signal reaches a phone by two paths, typically direct and reflected - such as among buildings or across water - constructive and destructive interference occurs which may induce varying reception strength from 5+ bars to zero. I would guess that those bars are based on received signal strength rather than received signal quality. Now also consider that your cellphone must act as a miniature tower with extremely low powered radiation whose signal must make the return path to reach the tower with sufficient signal strength and integrity to maintain a satisfactory connection. The reliability of this system is improved by adding towers to fill in shadow zones caused by geography, structures, and distance, but the complexity of the phone and multi-tower array requires additional sophistication as well. Also, the tower power out is probably a function of power sharing among tower users, the number of signals carried, and FCC environmental limitations. Considering voice calls, text and instant messaging, music and video streaming, and all the other features which we are being convinced we cannot do without, this system is being asked to do a lot in our unforgiving geographic region. I only have personal experience with Sprint, Cingular, and Verizon across the country and in the PNW. Since service is relatively imperfect among all companies, customer service takes on more importance. Consumer Reports and various internet sites' surveys placing Cingular at the bottom and Sprint nearly there are for good reason in my experience. Verizon's local customer service is little better but once one reaches a higher, out of area "supervisor" the results approach what I would call respectable. So what is the best of both worlds? These forums are helpful (also look at cnet and consumersearch) but it is better to query people on the street in the area where you will be relying on cell phone connectivity the most. It's a good way to meet people and everyone has honest horror stories to share. Two details to pursue over all others with cell users who are satisfied are their service provider and the make and model of their instrument. The local provider with the most owned (and leased / shared) towers determines your coverage but it is the cell phone itself which may be the final determinant. Each instrument is very different and the phone which may be best for your circumstances may not be offered by the provider of your choice, or the provider may have disabled the features you want. This is further complicated by the providers who limit your trial period(which I found is not really "free") and the number of phones you can experiment with during that period. So you are back to asking the highschool kids within that + / - mile swath of your cell phone usage area. But they are savvy and demanding consumers and will probably give you the best consensus compared with hours of internet research or unsatisfactory hype from the providers' salespeople. I personally would choose Verizon here but I am surviving with a landline until they offer a satisfactory instrument for my purposes. Of all their phones, only the Motorola E815 satisfactorily achieved and maintained a usable signal under dynamic circumstances for me but at the expense of less than 1 / 2 the expected battery life to do so... One version of the RAZR seems to work well for one friend but not all. I hope this helps.

If I stand in one spot on a bluff, I can get reception sometimes. Other than that, you can count on not being able to make a call.

No reception at all in downtown Winslow on T-Mobile. Can make calls from my home near the Library, but only if I stand up and / or lean against the window. Also can't make calls during a long part of the Seattle-Bainbridge ferry ride. When my calls drop, Verizon users are still talking. (Yes, I'll be switching!)

Always full bars. Think that Cell Tower is in Masonic Temple Parking lot, across from BHS.

Zero reception, on the West side of Bainbridge. Reception starts at Fletcher Bay and High School Road. 2 bars at the High School.

Hwy. 305 and the Winslow area have good coverage. Never any dropped calls from my residence near Winslow. Only 1 bar, but never any complaints on both ends. There are some problems in the most rural parts of the island especially inside buildings, but a signal was reported.

I don't get reception at home, but i do when I go to the major parts of the island. When I'm at home, I have to use my mom's AT&T, but when we're in Winslow, I get excellent reception. The phone, if the antenna breaks, is useless. I've had to replace it twice.

T-Mobile GSM reception on Bainbridge Island is very spotty. I like in the downtown "core", 15 minutes from the ferry. At the ferry, if you don't move, signal strengh is 2-3 bars. Walking up the hill to the main drag "Winslow Way" and go to the grocery store (T&C Market) , you're in a hole. If you stand on the park bench in front of T&C (and if the stars and sun an planets are in the right conjunction), you might be able to "phone home". Walking up the hill 1/2 mi to my house (near Wallace Way), you're still in the hole. I barely get reception on the 2nd floor. Walking another 1/2 mi to the Bainbridge High School and a 20-30' higher elevation, FIVE BARS. You can hear me now. This whole scenario is a metaphor for T-Mobile's poor service due to an underbuilt GSM network. So, in ZIP=98110 (Bainbridge Island), you will get service. You may just have to reenact the "Can you hear me now" game to make a call. By the way, sea kayak over to Blake Island, and T-Mobile GSM works fine.