Imgbash

Not only an alternative, but one on steroids! Here are a few of the improvements.

• The best of Tumblr and Reddit combined From Tumblr: Easy image browsing/discovery, reposts, likes, comments (and more) From Reddit: Everybody can contribute and post images.
• Image blogging Efficiently blog images. Uncompromising, fully focused on images.
• Customizable From hundreds of style related options to fully customizable html templates.
• Full, preview and thumbnail browsing Browse through full sized images, preview images, or the usual thumbnails. You choose.
• Fast and free Sites are fast and responsive, and it doesn't cost you a dime.
• And a lot more Galleries, folders, bookmarks, boxes, comments, widgets, users, themes, style sets, awards, point levels, branding, etc.