I would say the discussion about a company reselling GL to corporate clients was enlightening on the subject.
In any case what I\'m starting to do is to put a footer that says:
\"Managed by xxxxxx\" or \"Hosted courtesy of XXXXX\"
That links to a page that explains AT THE VERY TOP that this application is run on Geeklog, a wonderful open source codebase and a link to GL.
That way you are above board and explain things to people.
If you are a consultant you can even explain that opensource is sometimes time consuming to install and manage, and that you offer the customization/implementation service for a fee. Or users can go spend 80 manhours learning, testing, reading the forums at GL and have some fun

Good luck