RAILS link_to external site, url is attribute of user table, like: @users.website
You can prepend url with protocol if it's absent:
module UrlHelper def url_with_protocol(url) /^http/i.match(url) ? url : "http://#{url}" endend
And then:
link_to @user.site, url_with_protocol(@user.url), :target => '_blank'
Looks like you need to stick the protocol on your link. E.g. you have www.userswebsite.com in your database, it should be http://www.userswebsite.com