As many as 25 million mobile phone subscribers in the US could be using their handsets as mobile wallets by 2011, technology watchers have predicted.

Analyst firm In-Stat said that mobile commerce, the transaction concept touted in the 1990s that never took hold, is set to take off.

The "mobile wallet" is now a much more versatile application, according to In-Stat, that includes elements such as membership cards, loyalty cards and other forms of identification.

"In-Stat believes that the market can grow only by adopting a technology that offers the most versatility in providing transaction capability and content discovery," said In-Stat analyst David Chamberlain.

"There are several technologies that could enable mobile wallet operations via handsets, including near-field communications [NFC], RFID tags, barcodes and visual recognition. Standardisation efforts around NFC may give that system the edge."

According to a recently published In-Stat study, the attitudes of US users towards mobile wallets are at best lukewarm. Roughly one-third of respondents are 'interested', one-third 'indifferent' and one-third 'uninterested'.

The most frequently mentioned barrier to the mobile wallet is the fee for its use (72 per cent of respondents), followed by security concerns about losing the phone and privacy.

The In-Stat survey also found that the mobile wallet is most appealing to technology innovators and early adopters, as well as subscribers who already rely heavily on their wireless phones.