U.S. road warriors say they could get more work done if they didn't have to deal with what they're calling "laptop lag," according to a new study.

Laptop lag is the time between when people receive e-mails with attached documents, such as Excel spreadsheets or PowerPoint presentations, on their mobile handsets and when they can get to a computer to view and possibly make changes to the documents, reports iGR, Inc., a wireless research consulting firm. While users can receive the e-mails on their PDAs, they often can't work with the attachments because of the small screen size.

"Many wireless users, both consumer and business-focused, access their e-mail from their mobile handsets or smartphones," said Iain Gillott, president and founder of iGR. "But the true value of wireless e-mail is being able to view and edit e-mail attachments. This capability will differentiate mobile e-mail solutions going forward."

A recent survey of 1,200 mobile workers showed that at least once a week 70 percent have an urgent need to view or edit e-mail attachments while away from the office. Nearly 58 percent said the ability to view and edit attachments while away from the office would increase their use of mobile e-mail. Another 63 percent called the ability to view e-mail attachments on their PDAs as important or very important.

According to statistics from Frost & Sullivan, there are 55 million mobile workers in North America.