Tumblr is a microblogging platform that allows users to post text, images, videos, links, quotes and audio to their tumblelog, a short-form blog. Users can follow other users, or choose to make their tumblelog private. The service emphasizes ease of use. You can customize everything, from colors, to your theme’s HTML. It lets you post to your blog through email. It’s one more easy way to blog from your desktop or mobile phone. Just grab your secret email address from the Goodies page, and add it to your address book or phone book.
You can upload photos of just about any size and Tumblr will scale them to fit your blog. The largest that photos will appear in your blog posts are 500 pixels wide by 700 pixels tall. If a larger photo is uploaded, the high-res version will be available by clicking on the photo.