stickies

Stickies is a free software to create stickies on your windows.

Main features:

stickies will remain where placed until closed, even through reboots.
customised appearance
store text or images
attached to a web site, document or folder so they only show when it’s on screen
Stickies can be transferred from one machine to another either over a TCP/IP network connection, or by using

an SMTP mail server or MAPI client:
Play a sound file on receive
Signature for transmitted or emailed stickies
alarms set to ensure you notice them at a point you choose
API to allow integration with other applications
(more…)