Getting root permission to change a file without leaving Vim

You know when you open a file on Vim and after some changes you realise you'd need root permission to save the changes?

I used to think that there isn't other way other than:

• Copy the content of the file
• Close Vim
• Re-open it with sudo
• And finally paste it again

It might be a bit harder if you're using Vim on a remote SSH session.

Well, it will no longer be a problem. Today I learned a neat way to achive the same thing:

viml
:w !sudo tee %

Thanks my friend Diogo Lisboa for the tip.