Today, Apple’s iPhone 4 turns one year old, and – wow, what a year it’s been!

Throughout the year, we’ve seen everything – from antennagate to locationgate, the launch of Retina-optimized apps and even an iPhone in space! (Though this wasn’t an iPhone 4.) However, now Apple’s fourth generation iPhone is one, we’ve got to discuss a few things.

First, what to do about warranty? Yesterday, we talked about the fact that today, the warranty on the very first iPhone 4 handsets sold will expire. Apple offers a one-year warranty on all iPhone handsets – once this has expired, you’ll have to deal with any problems you encounter with your handset yourself.

What you do with your own iPhone 4 really depends on whether you’re planning on purchasing the next iPhone, which many expect to be released in August or September this year. If you’re going to trade-in your handset, or pass it on to a family member or friend, then do you need to worry about its expired warranty? Because once you purchase a new iPhone, you’ll get another one-year warranty.

During the last few days of your iPhone 4′s one-year warranty, you could look into getting the handset’s battery replaced. Over time, the battery life of Apple’s iPhones decreases, and batteries may be replaced by Apple Store Genius Bars while the handset is still under warranty (provided the battery needs replacing). There’s no guarantee you’ll be successful here – but if you’re looking to keep your iPhone for another year, or even if you’re planning on passing it on, having the battery replaced might be a good idea. Furthermore, Apple might replace your iPhone’s headset, too.

The other option (besides from doing nothing, and hitting the Genius Bar) is purchasing AppleCare for your iPhone 4, which extends the warranty of the handset past the one-year limit. Currently, these retail online for $69.00. We’d recommend you considering this option if you’re looking to use the handset for another year, as opposed to purchasing the iPhone 5 when it’s released.

Of course, whether you choose to stick with the iPhone 4 or upgrade to the fifth generation handset is a debate in itself, and revolves around the question of outdating – namely, how long will it take for Apple to drop support for the iPhone 4?

We’ve discussed this regarding the original iPad before, and with the iPhone 4, we feel the situation is promising – mainly because Apple is continuing to support the iPhone 3GS with iOS 5. Apple’s iPhone 3GS shipped with iOS 3.0, and is compatible with iOS 4 and iOS 5. If the iPhone 4 follows suit, you can expect the fourth generation handset (which shipped with iOS 4 and is compatible with iOS 5) to also be compatible with iOS 6, at least. Meaning that, if you’re concerned about having an outdated handset, you shouldn’t think about upgrading until 2013.

Obviously, this is all speculation – but it’s educated speculation, as I’m sure you’ll agree: The iPhone 4 is a powerful smart phone, and we think Apple will support it at least up until iOS 7.

In short: The iPhone 4 turns one today, but it’s going to be around for a while yet.

So there you have it – your iPhone 4 options, laid out in front of you. Either stick with the handset and forget about warranty (hey, there’s always phone insurance), upgrade to the iPhone 5 in fall or purchase AppleCare. Let us know which option you’re going to take in the comments.