I use a spray glass cleaner which we use for cleaning our safety glasses at work.

oops, should i have said that, "they said i could have it, honestly officer"!!!. Just a quick spray and a wipe with a glasses cloth gets those greasy marks off the scopes and binoculars. This particular spray also has an anti dust and static agent in it, plus it evaporates pretty well and leaves em sparkling. I haven`t got any at hand to tell you what it`s called at the mo, ran out and got to get some more, but will post it when i find out.
wadashot