What happens when your cell phone slips out of your pocket into the sewer drain? In tight economic times, the answer may be to shop for a used replacement.

A new Blackberry Pearl 8120 costs $200 on ATT.com, but the company also offers a refurbished Blackberry Pearl for $80. Can you trust the used model and save the $120? AT&T stands behind its refurbished phones with a 90-day warranty.

"Refurbished phones are pre-owned cell phones and devices that have been returned during the 30-day trial period. Each refurbished (device) is independently tested and reflashed with the latest software to meet new factory standards," the company said on its site.

From CraigsList.com to Ubid.com to eBay.com -- even your local pawn shop -- there are unlimited opportunities to save a bundle on consumer electronics. In 2005, more than 5 million units were sold used, according to Joanne Sonenshine, the senior manager for environmental policy and sustainability at the Consumer Electronics Association.

Not all devices are created equal, however, when it comes to resale.

"Products with a lot of moving parts, such as printers, faxes and scanners (are better bought new)," said Richard A. Troia, of I-Manage.com, an Omaha, Neb., computer recycler.

Add to that list projection television sets and DVD players. DVD machines have a lot of moving parts. Projection TVs require expensive replacements bulbs, and when you buy them used you can't be sure how much bulb life the projector has remaining.

There's a debate over the wisdom of buying used computers. Troia said it depends on the intended use. He said a lot of people donate their old computer, thinking they're doing a good turn for a school or nonprofit group.

"The problem is that most of the items are old and not powerful enough to be of any lasting benefit. If a person or business is going to donate, they need to ask whether the items fit into the technology plan of the intended recipient," Troia said.

At Omaha's Friendly Computers, Rob Farmanek rebuilds some units as part of his computer repair business, but he said that mostly low-use and low-income buyers will take a chance on a used unit.

"Used towers offer discounts for low to moderate users," Farmanek said. "Sometimes, parts can be newer inside. Some (used buyers) are older and are just starting out. They don't want to start with even a $600 new system."

Farmanek said he doesn't resell used keyboards or mouses. Wonder why? If you ever eat lunch over your keyboard, peer between the keys for the answer.

eBay.com offers consumers tips on buying used. UBid.com works directly with brand-name sellers to offer refurbished electronics of every stripe with a "100 percent fraud-free guarantee." CraigsList.com, in its code of conduct says it will investigate transactions gone bad or items that aren't what they promised they'd be, but CraigsList.com "is not responsible for content made available through the service."

The Consumer Electronics Association warns buyers of used products to know there are no labeling standards in law for terms such as refurbished, though the Environmental Protection Agency is considering such a system.

Sonenshine said that purchases made directly from another consumer should be particularly thoughtful. Turn the device on and off and test its use before sale.

Why buy used, especially when technology is advancing so fast? Experts said price and civic duty drive most people on both sides of the equation. The buyer gets technology at a discount and the seller might stash some cash. RapidRepair.com offers online estimates of what some used products are worth.

Environmental Benefits

Both buyer and seller may feel they're helping save the environment by giving an unwanted device a new life.

The CEA found that one in four consumers recycled a consumer electronic product in 2007.

"Consumers are becoming more aware of how much we're consuming and wasting. We see it as a resource conservation issue," said Sonenshine.

The CEA offers a site to help consumers learn about recycling and find drop-off locations in their communities at MyGreenElectronics.org. The site extols the virtues of the four R's: reduce, reuse, recycle and rethink.

"Re- products provide great value technology for a lower cost," Sonenshine said. "As people are trying to new tech, there's no question a re-product would provide great value for a lower price."

Though seven in 10 consumers told the CEA in a recent survey that they'd like to recycle electronics, 42 percent of people who got rid of a TV last year said they opted for the trash. Rising environmentalism has sparked a debate about what happens to electronics left in a landfill.

"EPA believes that the disposal of electronics in municipal solid waste landfills is protective of human health and the environment if that disposal occurs in modern, properly managed municipal solid waste landfills," an EPA spokeswoman said in an e-mail. "However, consumers and businesses today have many options to either donate or recycle) used electronics and we recommend these options first."

The EPA offers information on eCycling online.

Finally, before you sell, be sure to nuke any personal information off the device, whether it is photos, phone numbers or hard-drive information.