That's it. I want to have terminal windows to be (half-) transparent in Unity 2d without wasting too much resources.
This question has arisen after an update from Ubuntu 11.04 to 11.10, after which I was happy to find, that I can switch from Unity 3d back to Unity 2d.
I have tried to use gconf-editor, but haven't find anything useful there (only a few entries about unity-2d in desktop–>unity-2d, which doesn't seem to be relevant).
Best Answer
Start the terminal, goto the Menu bar -> Edit -> Profiles, click on the Default profile, then Edit, click on the Background tab. The bottom half of the window lets you mess with transparency. YMMV