I resurrected the GraphViz Sitemap Generator I created 5 years ago. The generator takes a file with tab separated values as input -- 1 line for each node of a sitemap or flow chart -- and outputs hierarchical or radial graphs as GIF and SVG.

The generator was on a long hiatus because I didn't want to keep maintaining it, but I dusted it off to do a quick graph. You can expect it to stay up indefinitely, but I don't predict it will get that much use since we have such good desktop tools for doing this kind of thing. It is nice for running large text files through it, however, which is why I use it occasionally.