XNote

Z 5 z 5 gwězdkow pógódnośony

wót Martijn dnja Junij 21, 2008 · trajny wótkaz

It's a great extension for keeping notes associated with specific messages -- especially the user interface is very convivial: post-it notes which can be placed anywhere on the screen (and which reappear anytime that same message is selected).
Only thing I'd like is that it would show somehow when a note has got the focus.