I don't know if I posted before about the Firefox addon Foxmarks which lets you synchronise your bookmarks online, however they've recently rebranded as Xmarks and added a whole heap of extra functionality.

 

When you install the addon you now have a new icon in the address bar, which if you click it displays similar websites, a review of the current website and other stats.

 

Take a look

 

Really handy for finding similar services quickly.

Wow! Looks great! I think I'll have to try it out.