As one of our dear visitors pointed out, it should now be easy to remove your account.
Go to the address listed below. There you will be asked to "Please specify the reason for removing your page" and a choice of 6 options.
Direct removal link: http://vk.com/settings?act=deactivate
If you signed up for Vkontakte using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Vkontakte. Click the icon below to find out how.