A site for the most voyeuristic ones among you, LookedOn lets anybody see pictures being shared on Twitter. The way the site works, users can see what others are sharing without actually following them. That is actually the main selling point of LookedOn – how it lets people see what others are up to without having to be an actual follower.
Searches on LookedOn are carried out just by furnishing the name of the person that one wants to stalk (or spy, or follow discreetly, or whatever name you want to give to what this site lets you do). Upon doing so, a gallery with all the pictures that person has uploaded will be produced. By clicking on any of these thumbnails you will get to see that particular image in its original dimensions.
There is not a lot more to add, other than saying that this site works without having to log in or reveal personally-identifiable information of any kind at all.
LookedOn.com In Their Own Words
Find Twitter pics on LookedOn.com.
Why LookedOn.com It Might Be A Killer
It is a great way to see what people you are not explicitly following are sharing on Twitter.
Some Questions About LookedOn.com
How is this done from a technical point of view? Which APIs are used? 
