When drug developers dream, many of them must wish for another 'Viagra'. Pfizer's launch of sildenafil ['Viagra'] in 1998 pulled the topic of male erectile dysfunction (ED) 'out of the closet' and into the culture of good health, advertising and everyday conversation. Indeed, the brand name 'Viagra' was splashed all over Atlanta recently when the American Urological Association (AUA) held its 95th Annual Meeting there [Atlanta, US; April-May 2000], from billboards to banners to entire sides of convention shuttle buses. The big question now is, who will be number 2?