I think the "???" is more of an expression of disbelief, along with the question. The sort of thing that would make a military person say "Whiskey Tango Foxtrot" if you get my drift. Example: "I have 2 prg's that I compared with WinDiff and they are exactly the same, but one runs and the other doesn't. WHAT is going ON???"

As far as the IMO, I think overuse of that is pretty crazy, but I can also see a use for it. When you are stating a known fact (possibly from a help file, or from MSDN KB??? <--rhetorical '3 question mark' question :)), it is not your opinion. If you are just speculating, you may want to let folks know you are just speculating. IMO :)

jfh