There's nothing you can't do at 3 a.m.

Once upon a time, everything shut down around midnight. Stores closed. Restaurants shut down for the night. Even television, after Johnny Carson did his thing, generally stopped airing programs until the next morning at dawn. Those days are long gone.

Want to work out at 2:14 a.m.?Anytime Fitness, an extremely fast-growing exercise center that bills itself as a solid alternative to expensive gyms, is open 24 hours a day, 365 days a year. And if it seems cruel to make some poor guy watch a desk at 4 a.m. or on Christmas, only to babysit a few knuckle-headed, muscle-heavy diehards, don't fret: the clubs aren't staffed 24/7. Members, however, can still come by whenever they want. They get electronic access key cards that give them access, even when the gyms aren't staffed.

Need a prescription filled at 3:39 a.m.? Oh, sure, we all know about the all-night pharmacies, but the KioskCom Self Service Expo in New York recently, saw he debut o f a pharmaceutical ATM (actually, they call it an APM). It's not out in cities yet, but if the company Parata Systems has their way, you'll be able to go to a machine that will work a lot like your neighborhood ATM. Only instead of cash, it'll dispense up to 448 finished prescriptions for its customers at any time, day or night.

Want to eat out somewhere at 4:01 a.m.? OK, sure, all-night restaurants have been around forever, and that fast food joints now have late hours: even 24/7 is old news. But it may be telling that earlier this year, Denny's changed the music it plays at the restaurant between the hours of 10 p.m. to 5 a.m. to alternative rock. As part of the new theme, staff has begun wearing T-shirts and jeans instead of their usual black pants and collared shirts. And they revamped the late night menu, serving dishes that were created by and for alternative rockers. Instead of the blue collar factory worker, targeting the younger crowd who often is up late at night, probably working out and picking up prescriptions.

Geoff Williams is a freelance journalist and the author of C.C. Pyle's Amazing Foot Race: The True Story of the 1928 Coast-to-Coast Run Across America (Rodale). He admits to usually nodding off around midnight.