Switched to T-Mobile from AT&T Wireless and found that T-Mobile has good coverage in the Seattle but poor / none in the San Juan Islands. Had to go back to Cingular to get good coverage in the San Juans. If you're near Semiahmoo, watch out to see that Rogers doesn't pick up your signal, otherwise you'll be roaming. You should be OK if you're in the hotel, parking lot, or Marina (great coverage!), but if you walk the beach, you'll likely be snagging Rogers' system.

Terrible service in Birch Bay. Available tower space to lease, yet Sprint neglects this entire area. Sprint deserves to eat the cost of accidental roaming on Canadian carriers. T-Mobile, on the other hand, has great service in Birch Bay.

Carrier T-Mobile in the Dakota Creek area Blaine, WA., has very poor / no coverage -- no bars. Once 1 mile out of this area reception starts to improve. We are 7 minutes from Canadian border / Rogers Wireless, out of all the cell phones we have tried, the only phones that won't roam in our area are Blackberry's. Other phones can be set to manually select carrier, but would switch by themselves back to automatic carrier selection and begin roaming again. When at home (Dakota Creek, Blaine WA. area) I put my phone in a northern facing window (3G coverage--about 3-5 bars, Edge coverage 3-5 bars, and Gprs 1-2 bars)to get a good signal, then connect bluetooth headset and talk that way. Had previously tried a signal booster to get better reception at home, with no improvement.