Since the iPhone was launched 15 months ago it has defined, for many, what a smartphone experience should be. But today T-Mobile gives the iPhone a run for its money with the launch of the G1 smartphone. From the details that have emerged today regarding the G1, Apple now has a reason to be looking over its shoulder.

View slideshow: The G1 vs. the iPhone

Here is a look at how G1 and the iPhone compare to one another.

Platform and Device

In contrast to Apple that built its own phone, operating system, and content ecosystem, the G1 is based on an open platform. That means any software publisher can design programs that run on the G1 and its Android operating system. The potential universe of T-Mobile G1 applications is huge. Yet, it's too early to know whether mobile application developers will flock to the Android platform.

At least for now Apple has the upper hand when it comes to the device. The number of iPhone mobile applications (accessible via Apple's App Store) is growing every day. However, Apple's total control over the iPhone can also be bad because Apple can choose to exert too much control over what applications run on the iPhone and bar those that it doesn't like, upsetting users.

Hardware Specs G1 vs iPhone:

Weight: G1 = 158g vs iPhone = 133g

Battery Life: G1 = 5 hours talk time, 130 hours standby vs iPhone = 5 hours talk time, 300 hours standby

Screen Size: G1 = 3.2inches vs iPhone = 3.5in

Camera: G1 = 3MP vs iPhone = 2MP

Storage: G1 = 2GB (expandable to 8GB) vs iPhone = 8GB or 16GB

Mobile Apps

The big difference between G1 and iPhone is how you put music, videos, games, and productivity applications on your phone. The iPhone has iTunes, mobile iTunes (for iPod Touch and iPhone) and the App Store.

Things work differently with T-Mobile's G1. The G1 doesn't require a desktop software porgram similar to iTunes to add content to your phone. Content can be added via a removeable storage card, but most content T-Mobile says will be downloaded using Wi-Fi connection.

Many Google applications will come pre-loaded onto the G1, for example push Gmail service, Google Maps functionality, Google Calendar, and YouTube. T-Mobile is only talking about a handful of third-party applications right now. There are likely loads more to be announced leading up the G1's October 22 debut. Some include a ShopSavvy, a program that turns your phone into a barcode scanner able to read UPC codes and deliver instant price comparisons and PedNav, and location-aware application that helps you find nearby public transit options and walking routes.

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