Samsung's Galaxy S phone is an excellent example of the smart phone genre. It – actually, they – is not only a good phone, but thanks to all the apps you can get, the Galaxy is also an excellent productivity tool.
As hinted at above, Samsung doesn't only offer one Galaxy phone but, rather, some variations on the theme. I happen to own a Galaxy S Vibrant, and recently spent a couple of weeks playing with the Galaxy S Captivate, a phone I don't like as much overall as my S Vibrant so far as usability is concerned, though I prefer the way you get at its battery.
