"TURN on, tune in and check out" has become the mantra of the merchandise-amassing millions who flock daily to the Internet to buy an assortment of things that would make even Timothy Leary scratch his drug-addled noggin.

We buy music over the ether, try on clothes from across the globe and pick pizza with our PDAs. According to a Nielsen survey, more than 875 million people worldwide have shopped online -- a 40% increase in just two years. Here in the U.S., online retail is even defying the gloomy economic forecast, with cyber sales expected to rise 17% this year to $204 billion -- and apparel leading all categories at $26.6 billion, according to Forrester Research.

With the information superhighway on its way to becoming as crowded as the 405 at drive time, even the savviest shopper needs to know how to compete. So, to help you beat the masses to the merchandise, we've gathered a few tips about when to wake up, how misspellings can help and why not to pay for expedited shipping. Below, some pointers from online apparel e-tailers we frequently visit.

Brooks Brothers

brooksbrothers.com

Brooks is one of many retailers that uses the Web as a testing ground, so sharp shoppers will find new prints, fits and even new pieces (that's how the brand's slim-fit boxer made it to store shelves).

Pay attention next time you see a Brooks Brothers catalog come in the mail; the company updates its site every two to three weeks to coincide with mailings. Men's and women's clothing and accessories go on sale in June and December and are marked down further in July and January. But everything remains in the site's clearance section (even the stuff from stores) through the entire next season.

Bluefly

bluefly.com

Set your alarm clock and brew some coffee, because hard-core fans of this site, which serves up discounted designer goods from the likes of Tory Burch, Vivienne Tam and Michael Kors, know that 250 new items are posted at precisely 3:31 a.m. PDT every morning. And limber up that clicking finger, because really hot items can sell out in just a few hours.

It might also help to mark your calendar; the entire website gets updated once a week, typically Wednesday mornings. That means all seasonal launches will happen on Wednesdays too (and usually in the first week of the month). For exact dates and other updates, including what designers are coming, sign up for e-mail blasts.

EBay

www.ebay.com

Once you've found your prey, the best way to improve your odds at this online auction site is to look for listings that expire at odd hours (think rush hour, dinner time or the wee small hours of the night), when your competitors are likely to be off their game. Also, shop on Sundays. They tend to be lightly shopped, and auctions that end on Sunday mornings and afternoons often wrap up at a lower value than at other times.

And don't be afraid to search the site for "Tom Frod" sunglasses or a vintage "Marymekko" dress. Failure to spell-check could mean failure to find for most prospective buyers -- and that could mean a bargain find for the sleuth.

Gap

www.gap.com, www.bananarepublic.com, www.oldnavy.com, www.piperlime.com

Gap Inc.'s sites are among the busiest on the Web, so signing up for e-mail alerts is crucial for staying ahead when it comes to new collections, sales and special events (you can do this from the home page of each site). The company sites are also a good way to get a gander at new a product that hasn't hit stores yet (new merchandise generally hits the Web a few days before it appears on shelves -- head for the "New Arrivals" section).

The Web also levels the playing field for customers who want limited-edition pieces that will physically roll out only to select doors (like the Gap Design Editions collection of white shirts, which will hit only 50 Gap stores this week, and Banana's upscale Monogram collection, which will be in only a dozen brick-and-mortar stores).