And with any big Apple product announcement, the rumors have been flying for months -- even former U.S. Vice President and Apple board member Al Gore has fed some of the speculation.

Times tech reporter David Sarno will be in Cupertino at the big event Tuesday, covering new Apple CEO Tim Cook's unveiling of the next iPhone, iOS 5 and maybe even Facebook-related announcements here on the Technology blog.

But, as of Monday, we don't know for sure what Apple will announce -- an iPhone 5 or iPhone 4S, an all-new lower-priced entry-level iPhone, one iPhone, two or even three new models.

So let's take a look at what's been reported so far, so we can see what pans out or what doesn't...

Specifications:

The standard right now for high-end smartphones (such as the Droid Bionic and Samsung Galaxy S II) is a dual-core processor, about 1 gigabyte of RAM, at least 16 gigabytes of storage memory and an 8-megapixel rear camera capable of shooting 1080p high-definition video and a better-than-VGA front facing camera.

The iPhone 4 currently runs on the Apple-designed and Samsung-built A4 single-core processor. The iPad 2 saw the debut of the dual-core Apple A5 chip, and the next iPhone is widely expected to gain the A5 chip, bringing it in line with its Android rivals. A boost in RAM would be needed to really capitalize on a faster dual-core processor, so these go hand in hand.

The iPhone 4's 5-megapixel rear camera is considered by many to be one of the most capable cameras available in a smartphone today, even at more than a year old. Nonetheless, a rumored upgrade to an 8-megapixel rear camera is expected and anything less would be disappointing considering how widespread of a feature this has become in competing smartphones.

Up front, the iPhone 4 has a VGA-quality camera (as seen on Apple's iPad 2 and iPod Touch), and that is rumored to be getting an upgrade too. An upgrade here would make sense, in part because Apple has already upgraded many of its laptops with high-definition cameras above their monitors.

The next iPhone is also rumored to be offered in storage sizes of not only 16 gigabytes and 32 gigabytes as is offered now, but also with a 64-gigabyte option.

Display:

The size of the next iPhone's touch screen has been a topic of debate and contradicting speculation for months. Rumors have ranged from the next iPhone retaining the 3.5-inch display of the previous four generations and an increase to 4 inches or even 4.5 inches.

Apple CEO Tim Cook The iPhone 4's 3.5-inch screen introduced the "retina display" with a resolution of 960-by-640-pixel and a crisp 326 dpi (dots, or pixels, per inch). The screen is so beloved by Apple iPhone owners that rumors have persisted since before the launch of the iPad 2 that the iPad would eventually see such a dense display.

Given how much iPhone users enjoy the iPhone 4's screen, this rumor may end up not seeing the light of day.

However, the fact that the next iPhone has taken more than a year to hit stores since the iPhone 4's launch has given rise to rumors that problems with producing a larger display are what have delayed the release of the next iPhone.

iPhone 4S or iPhone 5:

Simply put, if the next iPhone has a bigger screen, it needs a new body, a new form factor. If the screen stays the same, it could make use of the same form as the iPhone 4.

When Apple moved from its second-generation to its third-generation iPhone, the name changed from the iPhone 3G to the iPhone 3GS. The form factor remained the same, but the internals were upgraded, and the S was added to the name to indicate the bump in speed and improved software of iOS 4.