Marijuana has been in the news lately thanks to that infamous photo of Olympic swimming champ Michael Phelps puffing on a bong. But imagine Phelps had been smoking a joint instead. It turns out he would have been contributing to the national coffers. There is a small federal tax on rolling papers and it is about to get bigger. I came upon that bit of trivia while researching the children's health insurance bill that passed Congress yesterday and was promptly signed by President Obama. The new program will be partially funded by big increases in smoking taxes. That includes taxes...