One of the first accessories you will want to get for your phone is a battery charger that plugs in to the cigarette lighter in your car.  One of the big reasons to carry a cell phone in the first place is to have a way to call someone in case you have car trouble, and if your luck is anything like mine, your cell phone battery will be dead the one time you really really need to use it.  Buying a plug in charger just makes sense!

The next accessory you will want to buy is some sort of carrying case.  Cell phones tend to take a lot of abuse, and a carrying case is a cheap way to protect your investment. 

If you're really hard on phones, you can buy a hard leather case for the best protection.  If you're into water sports, you can buy a waterproof case.  But for most of us, a standard soft leather case will help prevent the little nicks and scratches that tend to collect on phones.

If you are going to be using your phone while driving, a hands-free headset or earphone is a must.  It's best to pull over when you need to talk on your phone, but sometimes that's just not practical.  If you just have to talk on your phone while driving, a hands-free headset is a cheap way to help insure your own safety, and the safety of other drivers on the road.

The accessories described above are necessities, but sometimes you just want to liven up your boring old phone a little.  If that's the case, then buy a cool snap-on faceplate or a flashing battery or a cute little keychain that flashes whenever your phone receives a call! 

If you're thinking about buying any kind of accessory for you phone, do yourself a favor and visit cellphoneshop.net.  From what I can tell, they have very very good prices on cell phone accessories of all types when compared to other retailers.