yfrog, from ImageShack, brings another picture and video sharing solution that allows you to post from a local file or a URL. The interface was clean and simple. You could log in via oAuth or wait to sign in after uploading your image and typing in your message to send with the image.
The service itself optimizes the images for displaying on mobile devices. They also support a large range of image and video file types, which was very impressive. yfrog is integrated into Tweetdeck as the picture sharing choice, so it works well on both your desktop and iPhone.