WASHINGTON — It's not just Vincent van Gogh who's dazzling American museumgoers. In New York, Jackson Pollock's paint-splattered canvases have been the talk of the city since the Museum of Modern Art put them on display last November. And in Boston, the Museum of Fine Arts just dismantled "Monet in the 20th Century," which drew more than 550,000 visitors in three months. Now the MFA is gearing up for its next blockbuster -an exhibit on Mary Cassatt, which attracted 4,000 visitors daily in Chicago. Museumgoing is definitely booming. Deborah Ziska, a spokesperson for the National Gallery of Art in Washington, says several factors are at play: Museums have become savvy promoters. They are selling themselves as cultural destinations for all ages and tastes, places to not only view art, but also to take in a concert, film, poetry reading, good meal, or have a family outing. The booming economy has allowed people the means to make leisure time more of a priority, and many people are choosing to spend that time and money at art museums. Viewing art can have a calming effect on an individual - a benefit that some high-profile Washingtonians don't take lightly, Ms. Ziska says. Tony Williams, the new mayor of Washington, for instance, tells her that he enjoys looking at paintings whenever he is mulling over difficult budget decisions. Certain artists are guaranteed crowd-pleasers. Fortunately for her museum, Ziska says, Van Gogh is among them. "His is a magical name," she says.