Hi-tech consumer goods, including the latest smart phones, will get slower and slower with use, experts have warned. The solution is the same process as applied to computer hard drives - defragging.

Since many high-end goods use micro-drives, which write and rewrite data as the appliance is used, over time files get scattered across the hard drive and take longer to piece together, resulting in slower menu switching and file access.

The solution is for a Windows program to read all the files and rewrite them so they are stored close together and in continuous streams.

However, mobile phone suppliers don't provide defragging instructions to users. A mobile phone hard drive could in theory be defragmented by connecting it to a PC via a USB port and then using the Windows program to defrag it. But mobile phone suppliers don't supply software or directions and if the procedure fails then all the data in your mobile phone could be lost.

Mobile phone hard drives are typically one-inch micro-drives made by either Hitachi or Toshiba. A Toshiba storage spokeswoman told us: "It is Toshiba's understanding that mobile phone users will not need to defrag a hard drive on their mobiles - that will be dependent on the phone manufacturer and how it sets up the file system on the handset. There wouldn't be a benefit to defragging a HDD in a phone."

But that simple assurance is contradicted by a a mobile phone operating system supplier, a mobile device storage tools supplier and an academic expert.

Symbian is a mobile phone operating system supplier. SymbianWare's v1.01 Stacker product for the Nokia 9200 Communicator includes the ability to compact the contacts database by defragging - removing unused blocks in its files. Such defragging saves space on the disk and speeds up working with contacts.

A support spokesperson at mobile device Storage Tools supplier SoftWinter said: "All our tests show that defragmenting significantly improves storage performance and mobile phones are no exception. It helps disk based (micro-drive) media more, but flash based media also shows significant improvement."

Christopher Clack is an expert on mobile phone RAM defragging at the Computer Science department in the University of London. He told us: "Providing mobile phones with hard drives is an interesting development that also raises issues such as whether there will be a virtual memory system that pages to/from that disk."

He thinks defragmentation is going to depend upon whether the mobile phone operating system insists upon file contiguity or not: "The mobile phone operating system might provide a PC-like file management interface to the applications, or might provide a different interface to the applications (e.g. all file blocks must be contiguous, or all file blocks must be the same size)."

Similar-sized file blocks won't stop fragmentation affecting performance: "If the mobile phone operating system provides a file system where all files are made up of blocks of identical size, then defragmentation will not be necessary on the grounds of memory utilisation - though it may become necessary on the grounds of performance, especially if file blocks are permitted to be distributed across the disk and if a paged virtual memory system is operated."

The same process also works on iPods. One report revealed that the digital music player speeds up significantly after defragmention, both in terms of accessing music and switching from menu to menu faster.

It's only a matter of time then that as devices get more sophisticated, with subsequent larger hard drives, that defragging becomes an everyday piece of maintenance.