RIM announced plans for its software store last October, calling it a place for developers to sell BlackBerry applications directly to users. Through a partnership with eBay's PayPal division, RIM will let consumers use the popular online payment system to buy the applications. Executives said the store would launch in March, and on Friday, RIM offered a sign-up list for users to be notified as soon as BlackBerry App World went online.

Though Apple's App Store wasn't the first online shop for mobile applications, it set a new standard for such stores and rode on the iPhone's success to change the way software for phones is sold.

Previously, carriers were the main channel for phone applications, but the App Store put a handset maker in charge. Apple said last week that there have been more than 800,000 downloads from a selection of more than 25,000 applications at the App Store. Google has already followed Apple's example with the Android Marketplace. There are more than 2,300 applications now available from that store, and the average user of a T-Mobile USA G1 handset has downloaded 40 of them, a T-Mobile executive said last week.

Microsoft has also outlined plans for a mobile software store, the Windows Marketplace for Mobile, later this year. Palm plans to launch a store later this year to work with its upcoming Pre smartphone.

Apple will be a hard act to follow for all the upcoming mobile stores in attracting great applications and shoppers, said Roger Entner, head of telecom research at The Nielsen Co.