Like Graham and many others, I use MM and iMM to help develop presentations, articles, project plans, etc. I have a "Map Central" linking to all my projects, which I find invaluable. I do agree with Graham on the subject of presenting with MM or iMM.
I have handed over solely mind maps to others (summarising for example the results of some market research I had done for them), but this has usually to people who I already knew were mind mapping fans. One obvious use that doesn't require much explanation is when mapping out a website strucutre for someone and I've regulalry done this with no problem.