I've been experimenting with Meshmixer's support options lately, as used for the Dizingof 'Joint Stars' print that I did, and also for some other things I'm still working on. It's a pretty neat (and free) tool, and I wrote up a blog post about it with some examples, and the settings I've found work best: http://www.extrudable.me/2013/12/28/meshmixer-2-0-best-newcomer-in-a-supporting-role/