These guys really know how to pick names. Firstly it was Flock then it's Fleck now and you must have noticed those names with "e" deliberately missed out such as "flickr".
Fleck will be something big, well before they get big you could see their little box called "LinkCloud" on my sidebar. You could add your links to experience it. Here is their blog and TechCrunch also wrote about them.
Just click "+Add a link..." in the LinkCloud box or CLICK ME to try.