A user on the site Ask MetaFilter queries other users there: How can I become less picky about what I eat?
A large number of replies suggest that the inquirer cook the food himself with the reasoning that it won't be "weird" or "gross" if he knows what's in a dish or how it's made. And many folks suggest reading Jeffrey Steingarten's The Man Who Ate Everything for tips or this archived article on Slate by Steingarten.
My trick, which at least one respondent recounted, is to wait until you're famished to eat—then almost any food tastes good. Ah, the old "hunger is the best sauce" solution.
What are your tricks?