Some rather random things I noted.
Homemade costumes saw a sharp rise at our place in 2009. In fact, originality in general had a sharp rise.
Costumes were far more varied and creative. Seemed like a lot more buying of a cloak or shirt or something and doing makeup from there than in the past.
About the most common costume I got was Spider Man, and it seemed to be pre-school ages, all of them.
Of the home-made ones that stood out, I had a lego block, a box of puppies (2 toddlers in puppy costume in a wagon with a bunch of stuffed puppies), the classic cardboard box robot, Raggedy Ann (didn't know kids even KNEW that one these days), and a rather creative viking.
Perhaps the down economy forced some more creativity?
Noticeably lacking were pirates and star wars, of which I got 1 Yoda, and a teenage girl pirate, and that was it.
Our treat bowl featured an assortment of full size candy bars, 'big grab' bags of chips, (12 oz)soda, and various fruit flavored 'candybars'.
A very pronounced and clear preference was seen:
Soda
Chips
Nestle
Hersheys
With the oddballs going for the fruit candies.
Seemed anyone over 8ish went straight for the soda and/or chips, and under went for the chocolate. With the oddballs going for the starburst/skittles types here or there.
Many would just open the soda on the spot, foregoing the treat bag.
The irony is this was more or less cheapest -> most expensive, as far as treats go. Much more Soda next year.
People are much more likely to strike up conversation with you when you are in makeup instead of a mask...