Today is the day! The long-awaited iPhone operating system software upgrade, better known as iPhone 3.0 has now been released. For our full review of the new iPhone 3.0 software upgrade, click here.

As iPhone fans rejoice about the new OS upgrade, they also have a few other things to cheer about. One is that Sirius XM Satellite Radio will soon finally be available on the iPhone, with a Sirus XM iPhone app coming out tomorrow, Thursday, June 18. The app is a free download, although you must be a Sirius XM subscriber paying the extra $2.99 per month premium for mobile access.

In addition, current iPhone 3G owners who have been complaining up a storm about the huge cost of upgrading their devices to the new and improved iPhone 3G S have caught AT&T's ear, and the carrier is thankfully doing something about it. Although most iPhone 3G owners are not yet eligible for an upgrade as their device is still too new, anyone who will be eligible in the next 3 months (through September, 2009) will be bumped up on the schedule, and allowed to upgrade as early as this Friday, June 19.

Without this upgrade eligibility, an iPhone 3G S 16 GB will cost current users $399 and the 32 GB $499, but with upgrade eligibility, the 16 GB will only cost current users $199 and the 32 GB $299.

Even at those prices, it's clear Apple's still doing something right because iPhone 3G S preorders for launch day (7 a.m. Friday) have already sold out.