The last two suggestions from Chris:
"2. Oil stains on the driveway"
Unfortunately I couldn't do this one - I looked in my driveway and wandered around the neighborhood peeking into parking lots and there were no oil stains to be found! I guess this means that cars in my area are properly maintained? I will keep an eye out for future opportunities. Sorry about that!
EDIT: Since I could do driveway oil, here's a photo of cooking oil/water/foodcoloring in a bowl, not quite the same but still fun.
"3. fresh fruit next to rotted fruit or some other contrast picture like that"
I didn't feel like waiting for my fruit to rot (especially with company coming this weekend), but I did do a contrast picture involving fruit... I even messed around with some post-processing effects, just for something different. Here tis:
Keep the suggestions coming!