Just a word of advice. The 4 may suit your needs now. But it's already being left out of features like turn by turn maps in iOS 6. If you are going to use it for a while you may be better off at least getting the 4s.
I'd wait (which I normally don't say, usually you should buy what you need), the price point for the 4S will drop (presumably) to what the 4 is now, so you could buy a super cheap 4 or buy a 4S for what you were planning on spending anyway.
These are two very important points that you should definitely think about before springing for an iPhone 4.
Not to mention the speed difference between an iPhone 4 and a 4S. I have an iPhone 4 because I didn't want to upgrade to the iPhone 4S last year when the rest of my family did because I wanted to wait for the iPhone 5 (or whatever it's called). My iPhone 4 constantly lags, Safari crashes when I have too many tabs open, apps can take a while to load, the camera takes considerably longer than the iPhone 4S's camera to load while also taking worse pictures and video than the iPhone 4S, it freezes up, etc. Compared to my iPhone 4, my sisters 4S FLIES. It never lags, all the animations are buttery smooth, apps load quickly, the camera loads very fast and takes excellent picture and video (not to say the iPhone 4 doesn't, because it does), etc. All of these little annoyances on the iPhone 4 can make it feel slow, laggy, and can cause some frustration (especially when apps that take a long time to load finally load and then crash).
And when the price of the iPhone 4S drops down to $100 when the next iPhone is announced, it'll be an even better deal than the iPhone 4. Like the poster above me said, the iPhone 4 is already starting to receive less and less features of newer versions of iOS; for example, in iOS 6, the iPhone 4 doesn't get turn-by-turn maps or Facetime over 3G like the iPhone 4S and the next iPhone will. This will continue to be the case when iOS 7, iOS 8, etc. are released.
Just some food for thought. Good luck!
