The other thing you can do with ctags which is pretty cool, is
vi -t IIapi_initialize
and it will take you to the first file with that symbol in and take you to that line in the file. It'll also load a 'stack' of other file references which you can then navigate through. There are different ways to do so :tn and :tp will take you to the next and previous occurrences respectively, and :ts will allow you to select from a list.
:help tags opens a help file with full description of how to use tags with vim.
