I haven't read of it, and it seems it has been around since a good time. Collecta is a search engine for things in real-time. It searchs on Twitter, Identi.ca, Youtube, Flickr, Blogs, Ustream and shows you what people is saying.
It's like a meta-searcher, I guess using API's from those services. But it has it's own API so it will be great for someone that's into web2.x and wants information on real-time from everywhere with just one API. There's a lot of people doing this already and there's a gallery about their development.
Maybe tomorrow I will get a little into it, it looks really nice.
BTW, it's what powers search.identi.ca