Here are some plain-talk tips that will help you get the most out of your I-Phone camera (not that this should replace your REAL camera... but hey, why not get the best image you can?)
Lighting is EVERYTHING. Always take a good look at how the light falls on your subject. Just moving someone a little closer to a window with light coming in, or turning their face so that sunlight can frame the contour of the face will make a huge difference! Every photographer will tell you, "Lighting is everything."
Filter up some FUN. Instagram not only allows you to post up instantly to Facebook, Twitter, Tumblr, and other social media sites, it also gives you some pretty cool vintage filters and cool borders. Don't forget to straighten, angle, crop, and use basic editing tools with Adobe Photoshop Express. And try out Color Effects if you want to shoot a black and white photo, but select just ONE color that will show up in the image.
Really cool app... try GLMPS! When you snap a photo through this app, the you will also get a few seconds of VIDEO before the photo is taken, giving it an amazing mixture of photo and video. Imagine reliving the moments that lead up to your photo AND getting the photo, too!
And, in case you need a self-timer for your shot (most cell phones DON'T have that feature), use Self Camera. No fancy effects here, but it will put a delay on your camera when you don't have anyone to take the shot for you.
So here are a few more suggestions for I-Phone creativity:
MoreBeaute2 - Airbrushing is NOT just for models anymore... you can give yourself a softer look in just two steps.
Tattoo Shop Lite - Oh, yeah. Tattoo whatever right on to your photo with custom words and symbols (especially good for those who want a little temporary rebellion without the long-term commitment).
Picture Effect Magic - Gives you the look of a high-quality pencil or paint quality image, and allows you to lighten/darken the photo right inside the app!
Now, for true inspiration... check out Rad Drew. He is one of the most incredible I-phone artists we've ever seen. His stuff is AHHHHH-some! You won't believe your eyes.