I will try to add more links about ECO when i found them, but, this compilation should be enough to have anyone moving forward on the "lovely" world of ECO.
Borland's Web Page
Borland's Developer Network: Make things fast with ECO II (video)
Borland's Developer Network: Create an ECO Space from an existing Database.
Borland's ECO Wikki
Creating a Blog with ECO.
How to do Things: ECO.
(The entire HowToDo site is built with ECO)
ECO related Blogs:
Jonas Hogstrom (Borland)
Jesper Hogtrom (Borland)
(i will suspect they are brothers eh?)
If you find more, please add comments with their URLs , so other people can use them.