It has been a long time coming, but eventually it had to happen Googlemail has now lifted the invitation only in the UK now. Of course this has been lifted for some time in the US.
Googlemail is what it has to be called in the UK and Europe because there was a recent law case regarding the name Gmail, there was a European based G-mail so Google were forced last year 2005, to drop the gmail and rename it googlemail.
It is possible for anyone to freely sign up to googlemail throughout, the Middle East, Africa as well as Brazil.
Product Page [Gmail]