Apple is breaking the padlock on the iPhone. The new version of the smartphone operating system will allow users to run third-party applications, the first time they've been able to do so with Apple's blessing.

The iPhone 2.0 software will run on the new iPhone 3G, available Friday. Most applications will also run on the iPod Touch, and on existing iPhones once the new iPhone 2.0 software has been downloaded.

QuickOffice for the iPhone will let you edit, view, and synchronize Office apps, such as Excel.
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Apple is requiring developers to distribute apps through its App Store, a part of iTunes. Developers will need to get approval from Apple before distributing apps, and Apple will take a 30% cut of sales.

In exchange for submitting to those restrictions, developers get to offload the distribution and payment-processing onto Apple, and Apple provides a big marketing boost.

When will we be able to download all these juicy apps? Well, um, actually, we're not sure. Apple isn't providing a specific day or time. You need the iPhone 2.0 software to run the apps. Stores will be opening at 8 am Friday to sell the iPhone 3G, which comes with iPhone 2.0 software installed. Existing iPhone and iPod Touch customers will get the iPhone 2.0 software pushed out on the Internet to them on Friday.

But users won't be able to get their hands on the third-party applications until the App Store goes online, and Apple wouldn't say when that will happen. It is widely expected to open July 11th or soon thereafter.

As developers are lining up to write and sell programs for the iPhone, we took a look at the applications in development, and picked the nine that looked most interesting. They encompass productivity, social networking, and just plain fun.

Quickoffice

Quickoffice is working on technology to eliminate one of the chief competitive disadvantages the iPhone has when compared with other smartphones: The ability to edit Microsoft Word, Excel, and PowerPoint files, and to sync those documents between the smartphone and desktop or laptop computers.

Quickoffice's iPhone service will be an adaptation of its existing services for Nokia, Palm, and Symbian devices. "Our heritage is doing the mobile office, and we will be bringing full editing capability to the iPhone as well," said Paul Moreton, VP of product management for Quickoffice. "Not only can you access files, not only will you have full editing, but you can e-mail them and share them. You'll have full collaboration capabilities from the iPhone."

Documents are stored on Quickoffice's server, which means that users will be able to access their files even when their Windows or Mac PC is shut down or otherwise disconnected from the network. They'll need a Wi-Fi, 3G, or EDGE connection from their iPhone or Touch to access the file initially, although the service also has an offline mode.

However, don't look for the service soon. Quickoffice expects it to be available late this year or early next year. Pricing will likely be similar to pricing for the service on the Nokia S60, $20 per year for up to 10 GB of documents.