Virtual world Second Life is to start charging users who want to customise their characters' first and last names.

The name feature - likely to be introduced by the end of the year - will cost $100 initially, and then $50 per year, according to Second Life spokesman Alex Yenni.

At present, Second Life residents can call their alter egos, called avatars, nearly any name they want but surnames are limited to a specific stock.

Linden Labs , the company behind the popular 3D fantasy world, have already approved special names to a select number of high-profile members, including IBM chairman Samuel J. Palmisano, and Democratic presidential candidate John Edwards.

The new feature was created to help legitimise Second Life, with a growing number of executives, politicians and otherwise famous people holding speeches and stage events in the virtual world.

Linden Labs said it would try to verify that avatars with high-profile names actually do belong to the same-named owners. Currently, it is near enough impossible to determine who is behind any avatar.