As the days get longer and the annual tax-filing deadline approaches, Benjamin Franklin's famous quip about the certainty of death and taxes should serve as an important reminder to investors who have flocked to Canadian income trusts. This market, which largely centers on companies involved in natural gas and oil exploration and production, skyrocketed in recent years on the huge spike in energy prices. Because these companies are organized as trusts, they are able to distribute tax-free profits to their shareholders and bypass a layer of tax that companies with more traditional corporate structures must bear.