iPhone 3G Image Gallery Photo by Kim Kulish

People who buy the next version of the Apple iPhone are likely to see a lot more games available for the smartphone.

Entertainment in the form of Web browsing, music and video are already a major part of the current version of the device. But the software development environment Apple has built for the new iPhone 3G appears to have drawn the attention of more game developers.

Out of the 11 companies that showed off their new iPhone applications Monday during Apple chief executive Steve Jobs' opening keynote at the company's Worldwide Developers Conference in San Francisco, three were game developers. They included Sega, which has built an iPhone version of "Super Monkey Ball;" Pangea Software, which plans to launch a physics-based puzzle and a racing game using cavemen characters; and Digital Legends Entertainment, a Spanish company that has build an action-adventure game for the smartphone.

"Apple is making a good phone, but it's something that can entertain you too," Mike McGuire, analyst for Gartner said.

Like other companies that showed off their applications at the keynote, game developers said they were attracted by the ease of use of the SDK available for the new iPhone. The tools within the SDK include a coding environment called xCode, an interface builder, an iPhone simulator for the Mac and the ability to test and debug applications directly on the iPhone. Apple also provides software instruments for testing the performance of applications.

Digital Legends claimed to have written its game of gladiator-like characters battling other creatures and warriors in a couple of weeks. The rest of the games were built in the time since Apple introduced the SDK in March.

What's unclear is the impact playing games will have on the iPhone battery. If they drain too much power, then the device will be less useful in delivering its core functions of voice communications and Web browsing, as well as its other entertainment features of music, video and photos.

"The battery numbers look good, relatively; but mileage is going to vary depending on how many of those different applications you'll be using," McGuire said.

Jobs claimed the slimmer iPhone 3G, which unlike the older iPhone supports wireless carriers' higher-speed 3G data networks, has a battery capable of 300 hours of standby, from five to 10 hours of talk time, depending on the carrier's network; five to six hours of high-speed Web browsing, seven hours of video viewing, or 24 hours of music.

If the numbers turn out to be true, then Apple is likely to introduce a lot of iPhone owners to electronic games.