Navigate | Symbol... (CtrlAltShiftN in the default keymap on Windows/Linux, CmdAltShiftN with Mac OS X keymap, CmdAltO in Mac OS X 10.5+ keymap).
Help | Find Action, type symbol to see shortcut in your keymap.
The above works globally across the project, for the current file only use Navigate | File Structure (or CmdF12 on Mac OS X 10.5+) and start typing the method name to narrow down the results, hit Enter to navigate to the selected method.
Related help sections:
- Navigating to Class, File or Symbol by Name
- Navigating with Structure Views