I find this one very useful, when you press just CTRL-G in vim you will get some basic file information:

"abc.tmp" 165 lines --36%--

When you use put count (a number) 1 before that command, the path will get expanded to full path (but shortened with ~ for the home directory). So when pressed:

1 CTRL-G

The output will change to:

"/tmp/abc.tmp" 165 lines --36%--