With the expanding shopping capabilities of smartphones, many shoppers are using their mobile phones to research and buy products—a trend that’s especially strong among young adults, says a new study released this week by Art Technology Group Inc., a provider of mobile commerce and e-commerce technology and services.

The study notes that 41% of consumers in the 18-34 age group have made at least one purchase via a mobile phone, compared with 26% of consumers ages 35-44, 18% of consumers 45-54, and 9% of consumers 55 and over.

The study, which was commissioned by ATG, is based on a July 2010 poll of 1,002 U.S. consumers age 18 and over by online research firm MarketTools.

Among all consumers in the study, 27% said they had used a mobile device for shopping-related activities such as searching for coupons, comparing prices among retail stores, receiving text message promotions, and viewing ratings and reviews. Among consumers 18-34, however, that percentage jumped to 46%, the study says.

Following are the percentages of consumers in the 18-34 age group in the study who said they have used a mobile device to:

Compare pricing among retail stores, 20%

Search for coupons, 19%

Seek customer or expert ratings and reviews while in a store, 12%

Browse through a merchant’s products on a mobile site or app, 12%

Find a store with GPS, 10%

Use a mobile bar code to learn more about products, 9%

Receive text-messages about product promotions, 8%

Favorite