You need the photo transfer app for your iphone to get photos from your iphone to your computer. It's a free download from the Apple store or itunes. You can also use itunes but it will transfer all the pictures and you can'r be selective like you can with this app.
I would suggest you use you digital camera software. If you don't have special software, I would suggest Kodak EasyShare. It works with nearly all digital camera's on the market, including the iPhone and uses the same interface on Windows and OS X.