Hollywood's hottest actresses aren't the only ones clamoring for a piece of Robert James Waller's Bridges of Madison County. The runaway best-seller written as the recollection of a National Geographic photographer has smitten book lovers flocking to the real Madison County, Iowa. ''I've been told there have been notes left on the bridges, and couples are beginning to picnic there,'' says Sherry Ellis, executive vice president of the local chamber of commerce. Iowa hasn't seen such fiction-inspired interest since Field of Dreamssent moviegoers in search of a mythical cornfield. ''Before, if we had 10 inquiries that was an exciting week,'' says Ellis. ''I would say an average now would be about 30 requests a day for our information packets.''
But Bridges fantasies extend beyond the heartland. The Washington, D.C., offices of National Geographic have received some 500 calls from readers determined to look up Robert Kincaid's Bridges photo essay. ''Many refuse to believe it's a novel,'' says National Geographic spokeswoman Barbara Moffet. Warner Books president Laurence Kirshbaum credits the response to an upsurge in mid-life longings: ''The idea of finding perfect love later in life is very appealing.'' The desire is real; the character isn't. According to Moffet, details like the logo on the hero's truck (''Robert Kincaid, National Geographic photographer'') plainly mark the book as fiction. ''That's another way of saying, 'Please steal my cameras.' ''