Recent shortages in petroleum have focused attention on and altered the economic feasibility of bio-based fuels.  One of the very important components of bio-based fuels is livestock waste.  It can be used for direct combustion, methane, methanol, bio-diesel, or hydrogen production.  These products are not only useful for energy; they can provide revenue for financing the total waste treatment process.  However, there are many challenges in moving the bio-based energy forward, and technological advances are being made at a rapid pace.