Was reading this site today about a guy who made a DIY Cintiq which seemed to work pretty well -
http://uk.youtube.com/watch?v=xZgUZwtd_Rg
http://www.bongofish.co.uk/wacom/wacom_pt1.html
And some other guy on youtube made a version with a projector -
http://uk.youtube.com/watch?v=g-qMJMQV604
Tempted to try and make one, there seems to be a fair few folk having a bash on their forums
http://forum.bongofish.co.uk/index.php
http://uk.youtube.com/watch?v=xZgUZwtd_Rg
http://www.bongofish.co.uk/wacom/wacom_pt1.html
And some other guy on youtube made a version with a projector -
http://uk.youtube.com/watch?v=g-qMJMQV604
Tempted to try and make one, there seems to be a fair few folk having a bash on their forums
http://forum.bongofish.co.uk/index.php