There are lot many places to store files online for free, for example Microsoft SkyDrive, ADrive. Recently Google Docs also started storing 1 GB data for free. There are also lot many services to host images and share them with a short URL, for example Twitpic. But at all these places, you need to sign up with your twitter ID or email ID, or your images will be seen with lot many ads running around. If you want to share only image, picture with your friends by uploading that somewhere then you may try Imgur.
Imgur is an online service started by a student named Alan Schaaf of Ohio University. This service is very very simple for sharing image, pictures with a single click. All you need to do is to upload the image from your local computer and then you will get a short URL. Now you can share that short URL with your friends. It also provides the HTML code to use the image on your own website by hosting the image on Imgur server.
You can use this service to share a picture having your email ID. This way you can stop getting spam on your email ID and share that as well.