I just organized one here in Pueblo, Colorado, it was broken into 4 sections
Section 1 was a digital photo section, where hunters would have to pick items off a list, find them, and photograph them. Each item was assigned a certain point value.
Section 2, I hid about 25 baseball cards around town, taping them under benches, under rocks, etc and then described their location, if a hunter found one, they received a certain amount of points
Section 3, a collected items section, where hunters would pick items off a list and actually physically collect the items. Each item was assigned a certain point value.
Section 4, was a find the answer section, examples, what color is the house at 303 3rd St, or what is the 10th word on the plaque in front of the female statue downtown. Each clue is assigned a certain point value.
At the end of the Hunt, teams break up into pairs of two and grade each others clue lists. It initiates strangers to get to know each other, laugh at photos, compare stories of the hunt, etc
Here is a link to our hunt, if you want to take a look.
Also, send me an email, firstname.lastname@example.org
if you want to use my scavenger hunt list, I will send it to you. You may have to change a few of the city specific clues, but other than that it should be ok.