Apple is stepping up legal threats against companies it accuses of infringing its trademarks. The computer giant Apple has written to two US companies asking them to stop using the word 'pod'.

Mach5 Products makes the Profit Pod, a device for wirelessly collecting data from arcade games or other vending machines. The device keeps track of how many coins are put into a machine and that information can be put straight into a spreadsheet.

But Apple claims the device is "confusingly similar" to its own trademarked music player iPod.

Apple has written to the owners of Mach5, Carolee and Dave Ellison, asking them to abandon attempts to trademark the Profit Pod name and stop using the term.

And they are not alone.

Terry Wilson set up a company last year to make TightPods - rather wonderful close-fitting covers originally designed for her PowerBook. The front page of her website promotes a tiger-patterned pod for users of Mac's operating system.

Wilson told ZDNet that she chose the name because using the cover was like putting a seed in a pod and because the word was a "hot buzz word - a part of the vernacular". ®