Watchlist: Add 'note' functionality to Watchlist, or to movies you've rated in general.

I keep a fairly long watchlist, and sometimes I forget how I heard of a film, or who recommended it to me.  Would it be possible / smart to add a 'note' field when I add something to my watchlist (and possibly when I rate a title) where I could log where the recommendation came from.  Then, when i watch it months (years) later, I could thank that person for the recommendation!  I could also track the location and who I watched the flim with, although that might be a little too OCD.