TORONTO, April 25 (Reuters) - Thousands of Canadian retailers already have equipment in place to let customers pay for purchases with a swipe of their mobile phones, putting the country in the lead in developing a system that could one day make cash obsolete.

All that's needed is an agreement between banks, credit card companies and telecoms, and that appears to be coming soon, promising to transform how Canadians pay for everything from their morning coffee to a tankful of gasoline.

If consumers embrace the system - and that's still a big "if" - clip-and-save coupons, transit passes, library cards and perhaps even driver's licenses could become things of the past.

"It is truly ground-breaking and revolutionary," said Stephen Gardiner, a managing partner for strategy at Accenture PLC, a consultancy that advises companies on mobile commerce.