Etags

creates tags file: in specified directory, etags -R *
M-x visit-tags-table File
M-. lookfor tags the cursor on
M-, back to original place
C-. open another window and show tags
C-, close tags window
C-M-, search tags, use TAB and mouse mid-button

[update 2/14/2013]
or use following to create table:
 etags `find . -name "*.c" -o -name "*.cpp" -o -name "*.h"`
C-. to locate, and C-* to return