Even as the economy sinks, sales at Wal-Mart, a bellwether in retail, have continued to grow. To keep it that way, the $379 billion company hopes several new Web 2.0 projects will secure what could become an increasingly illusive consumer dollar.

Prices for products we buy every day are jumping. The Consumer Price Index is riding more than 4% higher than a year ago, oil is trading at all-time highs. At gas stations across the U.S., a gallon of regular costs, on average, $4.10.

If people are spending more on basics like food and fuel, they likely have less to spend on impulse and extras. Technology to lure customers to stores, either physical or online, can be a differentiator, says Katie Delahaye Paine, CEO of KDPaine & Partners, a Web measurement consulting company in Berlin, N.H.

Several retailers are stepping up their use of Web technology to make shopping easier or build communities online. For example, JetBlue assigns staffers to chat with Twitter users and post travel news to the microblog service. Starbucks launched a Web site soliciting product and service ideas from visitors, who can then discuss and vote on ideas pitched by others. Costco, already a discounter, offers "treasure hunt" deals exclusively at its Web site, such as the Emergency Food Supply bucket (275 pre-mixed servings for $79.99, gift messaging available).

Now Wal-Mart is pushing into Web 2.0 territory with several initiatives that mix service and marketing under the theme of stretching consumer dollars.

"Push" is the operative word. Paine is unimpressed, saying the retail giant is using Web 2.0 the wrong way: to push its own ideas out, rather than let consumers express themselves and bring new ideas to it.

Wal-Mart offers a widget that you can download to your desktop to display a new tip each day for enjoying summer at home instead of vacationing somewhere else. Recent missives from the "101 Days of Summer Staycations" widget (get it? stay-home vacation?) include directives to hold a luau (and buy a $298 grill), let the kids camp in the yard (and buy a $14.83 sleeping bag), and, for kicks, take your dog to work (and buy $7.88 designer leash).

Product pitches don't accompany all the advice. Tips about capturing summer memories in a scrapbook and taking your children to the library, for example, stood alone.