Picasion.com is an online application that lets you instantly create animated gifs online. You can upload images from your hard drive and grab images directly from Picasa Web or Flickr. Just enter a Picasa Web or Flickr username and/or tag to see the list of pictures you can import to your animation. There are a few simple options you can use, you can choose the size of your resulting animation from the list or adjust it manually and you can select the frames speed in your animation. Picasion doesn't require for Flash, any registrations or something like that. It's simple and free.