Vim - find occurrences in files.

Vim is the editor for anybody using the cli on daily bases. One useful feature it has is the find/grep into files. Obviously you can exit or suspend vim and do a find or grep however not many know that vim has this built in. You can simply use vimgrep and the likes - for more info http://vim.wikia.com/wiki/Find_in_files_within_Vim.