Google has launched a version of its calendar service for mobile phones. The service is free but users must have a mobile phone plan that allows for web access.

Google Calendar will be accessible by visiting the normal Calendar website, where mobile users will see a list of upcoming events from their schedules.

A mobile version of Google Calendar has been in the works since the service launched in April 2006.  

"We realise that more people in the world have mobile phones than have computers, and people take their phones with them everywhere," wrote Google software engineer Devesh Parekh on a company blog.

"Since one of our main goals on the calendar team is to make planning events and maintaining schedules as easy as possible, starting today you can access your Google Calendar account from your cell phone."