Have you ever seen the flashcards with pictures where something is wrong or missing? The kids have to look at the picture and explain what is wrong. The picture might have a child holding the string of balloons, but the balloons are hot-air balloons - something of that nature. Well, you can make this yourself very easily and very inexpensively.
What will you need? construction paper, old magazines (from around your house or collect from friends/family members or doctor's offices when they throw them out), scissors, glue, laminator (if you have access to one and want to make them more durable).
Advertisers are always trying to come up with something clever. Many times, that will come in handy for this type of activity. You can find pictures with something that is "wrong" (but the advertiser is trying to make a point or be humorous). Simply cut that picture out and glue it onto some construction paper. I like to put them in a large manila envelope. You can really start collecting some great ones! Another great benefit is that you can always be adding to your collection and so the kids won't learn one set of flashcards without mastering the skill. You could also have them look through the magazines to try to find something that seems "wrong" or "out of place" - then you have little minds helping you find the pictures.
Example... this is my most recent find... a Hidden Valley advertisement.
Let the kids look at the picture and ask them, what's wrong with this picture? Hopefully they will say, "those kids have vegetables in their ice cream bowls" or "they put whipped cream and a cherry on top of their veggies!"