My biking buddy has tailbone pain from an injury years ago. She found that a saddle with a split rear portion made a huge difference in her pain. I can't remember the exact model she got (it's rather hard), but look around. There are lots of different saddles with a split rear, and your choice will depend on your sitbone width, whether you need/want a cutout, etc. Check the saddles threads here on TE -- there are many of them!
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow