The 3GSM conference in Barcelona has only just begun, and already Yahoo has made two major announcements.

The company has launched its mobile phone advertising system that was first trialled in Japan across eighteen countries.

The move marks an effort by Yahoo to expand beyond computers and put its stamp on the mobile phone advertising market that is set to explode thanks to the advent of high-resolution, relatively large phone displays.

The advertisements will run along the top of Yahoo's home page when using mobile phone internet browsers.

Users can click on the ads for more information, or call the advertiser directly.

The UK is amongst the countries in Western Europe that will see the ads, along with Germany, France, and many others. North America, Brazil, and Asian markets will also have the system.

Yahoo also announced a new marketing partnership with LG that will mean that Yahoo's services are put on to many of LG's mobile devices.

The soon-to-be-preloaded services include Yahoo Go for Mobile 2.0, Yahoo Mail, and Yahoo Messenger, as well as Yahoo oneSearch designed for mobiles.