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Continuing with a very source agnostic digital book strategy, Barnes & Noble has announced it will soon be offering an e-reader app for the Apple iPad .

With iPad preorders officially starting tomorrow, attention has shifted to iPhone 4.0 software and what features it might bring to both the iPad and future iPhone models. Apple Insider is now adding fuel to the long-standing rumors that the next big update to Apple’s iPhone OS will feature support for multitasking — that is, the ability for third-party apps to run in the background.

Last week, an App Store error got the latest version of Foursquare for the iPhone into a few users hands a little bit early. That hiccup resulted in the app briefly disappearing from the App Store before finally returning early yesterday . Now the newly designed version of the app is in the App Store and available for everyone to check out.

Last night at its Campfire One event, Google officially launched the Google Apps Marketplace . The Google Apps Marketplace offers third-party developers and services a way to integrate directly with the Google Apps platform and sell that integration at whatever price point they choose. This is a huge win for the cloud because it finally allows other cloud services to tap into some of Google’s APIs for things like Gmail and Google Docs at a much deeper level, which can benefit their own customers, as well as offering additional value to Google Apps itself