[Hampshire] sudo

I've always thought that having no proper root login on Ubuntu (Dapper) was
pretty stupid, but can anyone explain this?

After working quite happily at the command line all morning, I suddenly got:

$ sudo su
Password:
chris is not in the sudoers file. This incident will be reported.

After another attempt:

$ sudo su
Sorry, user chris may not run sudo on localhost.

So, NOW what do I do?

Chris.