The highbrow tradition of the theater and the lowbrow phenomenon of celebrity culture seldom go hand in hand. Usually, the only times the two worlds converge is when a Hollywood A- or B-lister decides he or she needs to be taken "seriously" as an actor by performing in something with no loud explosions, and preferably by Shakespeare. Occasionally, though, these two areas do come together on a decidedly less erudite mission, and the results of this unorthodox partnership can currently be seen at Don't Tell Mama. The Misadventures of the Wholesome Twins, running through Dec. 19, is a musical parody based on the travails of America's favorite twins, the Olsens