2viewis a neat little tool that lets you add Flickr-like notes to any photo online. If you're unfamiliar with Flickr's note system, a) you should read our Newbie's Guide, and b) you're really missing out on some fun to be had with photos that are shared online. Flickr's Notes feature lets users add their two cents to a picture, and mark certain things of interest with a very specifically placed caption. It's the Web equivalent of a sharpie marker, although a little less permanent.
To use 2view, just plug in any old picture URL. The photo will be routed through the service, which will overlay its notes on top. To share it with others, you can send them the URL, e-mail it, or embed it on blogs, Web sites, or social networking profiles.
2view adds a dash of social democracy similar to StumbleUpon, with "thumbs up" and "thumbs down" buttons users can click. If a comment is nixed enough, it will disappear from the photograph completely. There's also an RSS feed for each note, so people can subscribe to keep track of new notes.
While Flickr's Notes feature is neat, it only works when viewing photos on the site. Even using Flickr's Embed feature won't bring your notes along--which is what makes 2view such a great idea. I've embedded a photo of some birthday party favors below, feel free to add your own note.