While most people see mobile as the answer to so many problems, research from Nielsen Norman Group sees it as another problem on the list.

The key finding showed that users are 35 percent less successful completing Web site tasks via their mobile phones than they are on a regular PC. The usability studies leading up to this newfound research was conducted in the U.S. and Britain, where Nielsen Norman Group researchers found that the average success rate for users to complete tasks via mobile was only 59 percent.

"A surprising and annoying thing was that it was so hard for people to actually access mobile sites," said Raluca Budiu, user experience specialist at Nielsen Norman Group, Sunnyvale, CA. "Some companies have mobile sites, but they do not direct users to them.

"Also, the preferred method of access to mobile sites is search, and search engines do not make it easy for users to find mobile sites," she said. "The issue of search engine optimization is huge, I believe, for mobile."

The 59 percent success rate of attempted mobile Internet tasks comes as a shock compared to the 80 percent average success rate of wired PC Internet.

Nielsen Norman Group claims that the usability sessions conducted for this study were reminiscent of the very first usability studies done with traditional Web sites in 1994.

The study excluded poor cellular signal as a reason for poor user experiences.

Besides signal strength, the researches identified four main obstacles encountered while trying to complete a task via the mobile Internet.

First on the list was small screen size as interactions become more and more difficult depending on how many options the user can see at any given time.

Researchers also found that a tough point for mobile Internet users is text input, as that function as it is particularly slow and error prone.

Download delays can create an additional problem for the user, as getting to the next screen often takes even longer than it would using a dial-up connection.

Marketers, more so than anyone else, know that making a consumer wait is the quickest way to lose them.

Finally, researchers stressed that Web sites designed for PC compatibility will most likely render improperly on mobile phones and create a whole new set of additional obstacles for the mobile Internet user.

However, there is still hope for mobile Web developers, publishers and marketers: User performance could be improved by 20 percent by creating mobile-optimized sites, according to Neilsen Norman Group.

"I hope that the 40 percent of mobile information needs that are still hard to address on the mobile Web today will get addressed easily," Ms. Budiu said.

"I also hope that we'll see people turning to the mobile Web more and more often, not just for things like news and email, but for real, more sophisticated information needs," she said. "I hope that mobile devices get to be more useful as information tools.

"Today, they are really effective as killing-time devices."