Here's a list of my fav keyboard shortcuts for moving around Vim rapidly. There are an infinite number of other great keyboard shortcuts in Vim, these are just the ones I use most and that come to mind right now for zipping around quickly. As you read this, fire up Vim and try them out :)
Feel free to point out any that I've missed out in the comments!
gg - goto the first line of the current document.
G - goto the last line of the current document
* - * is a great shortcut, it finds the next occurence of the word your cursor is currently on. The '#' key does the same but backwards through the current document, though I have # mapped to auto comment blocks of code/script.
'a and ma - using the keystroke 'a will set a 'mark' named 'a' in the document at the current line you're at. Hitting the ma keystroke will take you back to the mark / line named 'a'. You can do the same with any letters in the range [a-zA-Z], just substituate a for the letter you want (mb mc md, 'b 'c 'd to mark/goto marks b, c or d).
% - whilst on a bracket/brace, goto the matching bracket/brace - useful if you're coding/scripting and you want to check if your brackets are closed properly.