Google on Monday invited programmers into a new sandbox that will let them test out significantly expanded possibilities for Web gadgets, small applications that can be hosted on the company's iGoogle personalized home page.

The sandbox, available at Google's iGoogle developer page, lets developers get started with a number of new features that eventually will make their way to the regular iGoogle home page, said lead product manager Jessica Ewing.

Among those new features are a left-hand region of the Web browser that lets users navigate quickly through a list of gadgets, a "canvas view" that can give gadgets more screen real estate, and the ability to take advantage of some social features for gadgets that employ OpenSocial standards. OpenSocial is an API, or application programming interface, that lets a gadget run on Web sites, such as MySpace.com, Ning, Salesforce.com, and Friendster, that support OpenSocial.

For example, with the features, somebody using a Pac Man game gadget could both expand the game to full-screen size and, when not playing, use OpenSocial's notification abilities to hear when a friend beat the high score, Ewing said.

"It makes the home page environment a lot more interesting and engaging," Ewing said.

Google has Yahoo on the defensive, but Yahoo has a bigger lead with its My Yahoo portal site than Google does with iGoogle. Other home page sites include NetVibes and PageFlakes, which was just acquired by LiveUniverse.

Ewing wouldn't say when the new abilities would be available to regular iGoogle users. "There are no firm dates yet. We're hoping soon," she said.

More details are available on the Google Code Blog and an explanatory YouTube video.

Google's news arrived the day before the Web 2.0 Expo begins. The timing was coincidental, but no doubt Web 2.0 programmers will be interested.