Apple iPhone vs T-Mobile Sidekick
[edit] Price
T-Mobile sidekick can be purchased for a minimum of about $100 without a contract. Apple iPhone can be purchased for a minimum of about $99 with a contract or $299 without.
An iPhone is required to use AT&T service unless it is jailbroken & unlocked. For an individual plan using the iPhone, the minimum price is about $82 per month - this includes unlimited data and 450 daytime minutes per month for voice calling. The AT&T plan includes several thousand evening/weekend minutes as well.
The T-Mobile Sidekick plan costs $1 per day for internet plus $0.17 per minute for voice calling. For a person who uses 450 minutes, this plan is likely to cost more than the AT&T plan. However, for a person who uses voice calling for only a few minutes per day and uses the phone's internet connection only a few days per week, the Sidekick plan might cost $30 per month in total, or less than half of the cost of the AT&T plan.
[edit] Features
Appealing features of the iPhone include: Safari web browser, which is compatible with Gmail and other prominent web sites. Google Maps integration for directions while you are on the go. A relatively large touchscreen which allows "pinch to resize" and scrolling by touching/"pushing" the screen.
