3GSM will see the launch of a partnership that aims to let you put a copy of your desktop PC on your phone's SIM card, and use it to work securely on any other PC.

Storage vendor, M-Systems and mobile software company Migo are putting a desktop synchronisation package on M-Systems' MegaSIM, a Flash-based alternative SIM card which will eventually store up to a gigabyte.

Users would be able to store and secure their documents, e-mail and browser favourites on their mobile phone, says M-Systems, so they could start to work on a remote PC, simply by connecting their phone, and back it up to the phone when they have finished.

The idea depends on handset vendors and operators putting big chunks of storage on the SIM, but this should be popular with operators, M-Systems argues in a White Paper, because it eases the limitations caused by fixed embedded storage, but lets the operator retain control, by keeping the storage on the SIM.

Operators could use the feature to include remote synchronisation of e-mail and documents on the user's actual PC, says M-Systems.

Migo already offers software for PDAs and Flash drives, as well as a USB watch, that lets users work with their own desktop on a borrowed PC "without altering the host computer or leaving data traces", said M-Systems.

MegaSIM is the same size and shape as a conventional SIM card, and compatible with legacy standards, says M-Systems. At 3GSM, they are showing software on the format, including video codecs, mobile virus protection software, music player DRM and payment solutions, and a file viewer.

"MegaSIM is the same size as a regular SIM, but has eight or nine contacts, instead of six," said Neta Yacoby, marketing manager at M-Systems. "It's not a major modification to add it to a handset." Orange is already running a trial service using 128 Mbyte SIMs provided by GemPlus, using similar technology to M-Systems' MegaSIM, she pointed out. "That's still low for multimedia use," she said, "but we will have a 1Gbyte version by the end of the year."