PUBLIC MARKS with tags app & flickr

Photo Frame turns your iPad into a stunning digital picture frame by showing a slideshow of photos from popular photo-sharing site Flickr. Photo Frame can load the latest interesting photos, recent photos and even your own photos, favourites and contacts' photos.

Portfolio To Go is the perfect iPad app for artists and photographers who use Flickr.com to showcase their photographs online.

I've developed a Facebook Platform application for Flickr users called "Friends on Flickr" that focuses on Facebook friend tagging of Flickr photos using machine tags and a simple, straightforward profile tab for sharing both your own public content and content tagged with your Facebook id in the larger public repository.

How do you create the future of Web apps? By accident. Caterina Fake and Stewart Butterfield (above) are the husband-and-wife team behind Flickr, the photo-sharing site that launched in February 2004 and quickly got so popular that Yahoo acquired it a year later. Flickr wasn't born as a fully realized idea--in fact, it wasn't even originally for photo sharing. But its building blocks make up a successful Web 2.0 application. Here's how it evolved.