Check this forum for some examples: http://goosebumps4all.net/34all/bb/forumdisplay.php?fid=28
But actually, I am interested in that too. Does noone know something better?
I've just put together what you may be looking for: http://graphdracula.net
var g = new Graph(); g.addEdge("strawberry", "cherry"); g.addEdge("cherry", "apple"); g.addEdge("id34", "cherry");
I used the previously mentioned Raphael JS library (the graffle example) plus some code for a force based graph layout algorithm I found on the net (everything open source, MIT license). If you have any remarks or need a certain feature, I may implement it, just ask!
As guruz mentioned, the JIT has several lovely graph/tree layouts, including quite appealing RGraph and HyperTree visualizations. I'd post a link, but as a n00b I'm restricted to one link per answer.
Also, I've just put up a super simple SVG-based implementation at github (no dependencies, ~125 LOC) that should work well enough for small graphs displayed in modern browsers.