To use this module, make sure that planner-wl.el is in your load path and add this to your .emacs (or _emacs):
(require 'planner-wl)
Then, when you call M-x planner-create-task-from-buffer from Wanderlust summary or message buffers, the task will be created with the correct annotation.
To add keybindings to Wanderlust, call:
(planner-wl-insinuate)
This binds C-c C-t to planner-create-task-from-buffer.