SanDisk has developed the world's largest capacity SD card, storing 4GB of data on a device little bigger than a postage stamp.

The card was announced at 3GSM in Barcelona, along with a conversion kit that allows users to link microSD Flash cards, miniSD and standard size cards.

The company hopes that this will end consumer confusion over card sizes, and boost data rich applications.

"Consumers shopping for memory cards do not always know what type of SD slot is in their mobile phone," said Jeff Kost, vice president and general manager of mobile consumer solutions for SanDisk.

"The microSD Multi SD Kit makes the purchasing decision a 'snap' because the card is guaranteed to fit, either directly through a microSD slot or by using the adapters for miniSD or standard SD slots.

"Retailers also get a break, because sales associates can focus on the benefits of added capacity rather than worrying about compatibility."

SD cards have become the most popular storage medium for camera and mobile phone users since their introduction, but differing form factors have caused confusion.

The new 4GB version will be released later this year and SanDisk is being cagey about pricing details.

The company also said that it expects more applications vendors to be selling the cards preloaded with their software, including mapping and games.