Cacoo is a new (beta) site for creating: graphs, diagrams, flowcharts, etc. It is very similar to Lovely Charts in that respect and has some really attractive options for users. For example, everything is done via a drag/drop interface which is ideal for any "Mac" user. Also, there is real-time collaboration going on via a chat; and the ability to have unlimited undo's. Finally, a person can share their media via an html code which is ideal for sites/blogs.
Below is a quick example I made in 3 min (very user friendly)...
Give Cacoo a try by clicking here.
For another excellent review check out Richard Byrne's amazing blog.