So the first day of Cannes and the first fight, Microsoft versus Symbian, a no-holds barred rumble.

Microsoft took the early lead by pre-briefing as many people as it could get hold of about plans to take over the operating system market. Then Symbian hit straight back with its Samsung deal.

The Korean firm is taking a 5% stake for £17m, which places a nice valuation on the joint venture of £340m. But anyone who thought Samsung was coming completely off the fence would be wrong. The company, the world's number three in the handset market, has signed up with Microsoft for a new PDA.

Symbian has taken a knock as well. The smart new 3G handset unveiled yesterday by Sony Ericsson - also a Symbian shareholder - does not use Symbian but SonyEricsson's own proprietary technology. Perhaps Symbian 3G is having as many teething problems as the network technology itself?

So who is that lurking on the sidelines? That would be Motorola. The US giant is also a Symbian shareholder but has yet to make a Symbian-based phone.

Some in Cannes, however, say the company is showing off a prototype phone using the Linux operating system.

A phone based on the Linux platform would go down well in China - where Motorola has a major market share - as the Chinese government has made it clear it prefers open source technology to the rather more closed shop that both Microsoft and Symbian run.