flickr is definitely one of my top picks for best design, easy on the eyes and easy to use. The iPhone application interface is so appealing that I actually have the desire to upload my photos to flickr, an urge that I do not have when I am using the website on a laptop or desktop computer. I know what you are thinking - could it really be that great? But, I'm telling you.. less is more is the name of the game. When you open the application, various breathtaking photos take turns more or less sliding across the screen.
To upload a picture, simply click on the camera with an arrow above it. The prompt will have you select either "Take Photo or Video" or "Upload from Library." See? Couldn't be any easier if you tried. Once you select a picture, you can add a title, description, add the photo to a new or existing set, add tags, choose your image size (resolution) and even geo-tag your current location. Or, you can add another photo by clicking the "Add Item" button. If you enable the setting, flickr will share your photos on twitter for you.
On the main menu, there are three other options (besides information). You can click on your recent flickr history, "you" where you can view your sets, tags and your photostream and contacts. That's all. You cannot do a lot with it. There are no fancy gizmos, but that is why this application is fantastic. Simple and efficient.