To all having tailgate woes -- there are a lot of us -- you can take action to put real pressure on Toyota to stand behind their products even when they don't stand up to normal use. Since a tailgate is something we rely on as truck owners, when it fails it is a safety problem. Follow this link to complain to the NHTSA:
http://www-odi.nhtsa.dot.gov/ivoq/
Here is a copy of what I submitted if it helps.
2005 Toyota Tacoma tailgate is dangerously weak, and is unable to support what most consider normal weight for a truck tailgate. Although substandard design may be considered "buyer beware", truck buyers expect a tailgate to support the weight of normal truck use activities. Toyota provides no warning or caution anywhere that the tailgate is of insufficient strength to perform normal 1/2-ton truck duties, and typically (per Internet forum threads) tells their customers that it is their problem and that they should not expect to be able to safely use the tailgate for anything more than hiding the inside of the bed. Since Toyota has produced a substandard designed part, they should have provided a visual warning on the part to alert customers to the danger their product imposes if used in a traditional manner. Since they did not do so, they should be held liable to provide a redesigned part to their customers or full restitution for the purchase price of the vehicles. A Google or similar Internet search on "Tacoma tailgate forum" will substantiate my statements beyond my personal experience with the tailgate bending.