The TV world turns upside down this summer, as the big broadcast networks open the spillway to a torrent of cheesy reality shows, while cable channels trot out meaty comedy and drama with high production values.

On the networks: Copycat dance and singing competitions join goofy games and voyeuristic examinations of supposedly steamy suburban lifestyles. D-list celebrities abound.

On cable: Established comedies and dramas with name stars return, and promising new ones premiere.

It's just another aspect of a crowded, topsy-turvy TV world where everyone tries to shout "Look at me!" while gasping for breath in the chase for the almighty dollar.

Here's how it used to be: Lots of people found better things to do in summer than watch TV. The networks saved their pennies airing reruns.

Here's how it changed: Cable channels, seeing a void, started to premiere their best shows in summer. Broadcast bosses blubbered, "We've got to do something." Sometimes when they did, they struck the mother lode.

Here's how it is: Cable channels continue to slot much of their best stuff in the summer. The network big boys (and girls) augment their reruns by throwing all sorts of cheap meat into the stew, dreaming of another "Who Wants to Be a Millionaire," "Survivor" or "American Idol," which all began as summer fill-ins. And lots of people still find other things to do in summer besides watch TV.

Those who tune out are missing plenty on cable: FX's "Rescue Me," the fireman sit-dram starring Denis Leary, and "It's Always Sunny in Philadelphia," which this summer picks up guest star Danny DeVito; "The Closer," TNT's tale of a brilliant detective (Kyra Sedgwick); "The 4400," believable alien escapades, and the endearing obsessiveness of Mr. Monk on USA; and, of course, TV's best show, HBO's amazing Western, "Deadwood."

HBO premiered the wildly divergent comedies "Lucky Louie" and "Dane Cook's Tourgasm" on Sunday. And on Monday, TNT's "Saved," starring Tom Everett Scott as an emergency medical technician, began.

Showtime unveils the ambitious drama "Brotherhood," about a politician and a gangster, on July 9, and USA starts "Psych" on July 7. It stars Corbin Bernsen and Dule Hill, with James Roday as a police psychic who's a complete phony.

The deep-pockets broadcast networks, where summer is low-budget, test-drive time, have nary a show that compares in ambition (and, most likely, in execution) to any of them.

The relatively low cost of most summer reality gives the networks a chance to swing at any sort of pitch to try to hit a home run. "Millionaire," "Survivor," "Idol": Each of those blockbusters more than paid for all the shows like "Tommy Lee Goes to College" and "I Want to Be a Hilton" that sprang up on their respective networks.

Sadly for NBC, Tommy and Hilton have been the norm. The only notable winter success, a term used loosely, that the Peacock has bred in summer is "Fear Factor."

In the fall-winter regular season just ended, the networks garnered exactly a 50 percent share in prime time, meaning that half of all the households watching TV at any time weren't watching ABC, CBS, NBC, Fox, UPN or the WB.

Count on that number to go down considerably this summer. Warm-weather cable-channel viewership passed that of the broadcast networks several years ago, and while one of the new summer broadcast shows (my money's on "America's Got Talent," produced by "American Idol's" Simon Cowell) might catch, most of them sound like strikeouts.