For those who haven't seen it or the New York Times article yet, the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation has recently conducted a long-term study on aspartame that everyone should be aware of.
The results of this mega-experiment indicate that APM is a multipotential carcinogenic agent, even at a daily dose of 20 mg/kg body weight, much less than the current acceptable daily intake. On the basis of these results, a reevaluation of the present guidelines on the use and consumption of APM is urgent and cannot be delayed.
(Emphasis mine; full paper in HTML here, PDF here)
Stay away from that shit, folks. Not only is it nasty, there's growing evidence it can really screw you up in an increasing number of ways.