Zack and Dr. Daniel MacArthur have already pointed to the Interpretome tool (Chrome and Firefox only!). As Daniel noted the PCA option will probably be the most fun for people. Just load your raw (unzipped) 23andMe data file, and project yourself onto different population sets. Since I know how to use EIGENSOFT this isn't too revolutionary for me, but I've been putting off analyzing my chromosomes' ancestry segment by segment. Luckily Interpretome has a much better experimental "ancestry painting" than 23andMe. Just make sure to use the HapMap3 setting to get the most juice. I used 40 individuals to compute my results, and it took less than 10 minutes. The reference populations below are African Americans, Bantu in Kenya, Mexican Americans, Gujaratis, Tuscans, and Chinese.