Lafazar: I just finished the Game and made a copy of my maps. I used the walkthrough on Gamefaqs which notes almost any secret with exact coordinates, so the maps should be fairly complete.
I marked the following things as points of interest (red squares) on my maps:
-Secret Buttons/Switches
-Secret Panels
-Teleporters
-Mana Circles and Healing Fountains
-Other Points of interest (Persons/Statues/other Objects)
Further notes:
-Sometimes I marked unimportant things (like chests), so do not despair if you find nothing critical or secret at a marked location
-I did not note the locations of important objects
I hope this is of use to anyone.
Edit: Argh! GOG keeps automerging my posts (Which is a real problem because there is a limit of five images attached per post). I got around this limit by repeatedly editing this post, but just to be sure I uploaded them to tinypic also:
Thankfully you did upload them because all the others have gone away and the stickys should be edited to reflect that.