It’s starting out as a day of fits and starts for Apple’s new mobile computing-related releases. The company’s service went down last night, as scheduled and it’s replacement, MobileMe, has poked its virtual head up a few times, but was not up as of this writing.

In the meantime, a new version of iTunes has been released through Apple’s Software Update mechanism. The update mainly provides access to Apple’s new Apps Store, through which it will sell applications for the iPhone and iPod Touch.

Speaking of which, the iPhone 2.0 firmware update is not yet appearing within iTunes, but an observant MacRumors reader apparently found the software’s URL by scouring XML files. To apply the patch, you must hold down the Option key when pressing the Check for Update button within iTunes. Some readers are reporting what they consider long restore times, but so far the update seems to be working for iPhone users. The update for iPod Touch devices is a paid upgrade and apparently not part of this software.

For those willing to take their chances, the patch can be found at

If your download appends a “.zip” extension to the file, simply remove it — don’t unzip the package.