Mobile phone operator 3 is offering free access to Twitter for all its customers through to the end of March.

"Whether you're using Twitter's mobile site, or taking advantage of a special integrated mobile app on phones like the INQ Mini 3G, INQ Chat 3G and the Sony Ericsson T715, tweeting messages and pictures is completely free of charge", says 3.

Meanwhile, 3 customers with an internet add-on can use Twitter without using any of their monthly internet allowance.

"We want to make the internet as easy and affordable to use on your mobile as on your PC.  Our 3G network is built for services just like Twitter, so throughout February and March we’re encouraging our customers to give it a try", says Charlotte Blanchard, director of products and services at 3.