Chances are if you have an iPhone 4, want an iPhone 4, or can spell iPhone 4, then you’ve heard all about AntennaGate. The synopsis is this: Touching both sides of the external antenna that cleverly wraps the phone is claimed to diminish the signal, negatively impacting operation. While I can’t say for certain if it’s a real problem (the return numbers don’t seem to be backing up the claims), Apple is trying to rectify the situation with free cases for all iPhone 4 owners.

In order to get a free case (at least for the bumper version) Apple has made it simple. You only need to download the case app and follow the instructions. You can find more information on the program itself at the Apple information page.

But what kind of case can you get for free? Well, obviously you can get a free case from Apple, but if that is not your taste then there are a select few third party iPhone 4 cases that you can get. Let’s take a look at your free case options.

Apple Bumper Case

Apple has, for the first time, offered its own case for the iPhone, and it could not have come at a better time. The case is designed to wrap around the edges of the iPhone 4, protecting it in case of a drop on its edge. Coincidentally enough (and here the wild theories could probably start), the bumper case covers only the antenna area.

Now, normally the Apple Bumper Case is offered in a variety of colors. However, Apple has taken a page from Henry Ford’s playbook and offering only the black case for free. Yes, you can have any color bumper case you want as long as its black.

Belkin Shield Case

The Belkin Shield Case is being offered as part of the iPhone 4 free case program, and it is a very thin case designed to offer some protection while still being very easy to handle. The case is made of hard form fitting plastic, and an equipped iPhone will still be able to slide out of pockets and purses without any problems.

Griffin Motif

The Griffin Motif case is a durable scuff and tear resistant case specially designed for the iPhone 4. The case is stiffer than popular silicone based cases but much more flexible than a hard shell case. Cutouts are in place to keep the important things easily accessible, and the sleek design doesn’t add much bulk to the thin phone.

Griffin Reveal

The Griffin Reveal iPhone 4 case offers a tough polycarbonate cover for the back of the iPhone with thin rubber protection for the side edges (or, as we like to call them, antenna). Probably the thinnest of the cases we’ve seen, the Reveal adds only 1 millimeter to the back and sides of the phone. This is one case that you won’t notice that much when stuffing the phone into a pocket, yet looks good on the device.

Incase Snap

The Incase Snap case is currently available only through the free case program. The Snap is a hard plastic cover with the usual cutouts for the important things like buttons and ports. The Snap is being offered in both smoke and clear (the color version in the picture are not part of the free case program).

Speck Fitted

The Speck Fitted case is a hard plastic case that sports a plaid design on its back. This case might be your choice if you are inclined to match your devices to your wardrobe or have a strong fashion sense. The form fitting two part hard case protects your iPhone 4 from scuffs and scratches while allowing access to all of the controls and sensors.

Speck PixelSkin HD

The Speck PixelSkin HD is a smooth and flexible protective case that offers a contoured skinny fit. The back of the case offers a polished artful look with a matte pixel overlay. The slim case offers decent protection in an eye catching design.

While these are the free case choices as of this writing, please note that, according to Apple (and usual for these kinds of programs), the case choices are subject to change. And another thing to remember is that, while free, getting the case is not an automatic process. That means you will need to register within 30 days of getting your iPhone 4 to get the case. And for existing iPhone 4 owners, don’t delay too long – you need to have the request in by August 22, 2010.

Another thing to note is that the program runs through September 30, 2010. iPhones purchased after that will not be eligible for a free case. Does this suggest that Apple has a fix in line for their flagship smartphone after that date? Well, to me it does, and the recent delay in shipping the white iPhone 4 until the end of 2010 would (at least to me) seem to confirm this, as well. The bottom line – get your free iPhone 4 cases while you can. They won’t be around for long.