All toddlers suffer from the "gimmes" at some point in their lives. It's that time when everything they see seems to have some magic allure that they just can't resist. While this might seem cute to you, kids who go around grabbing everything can quickly turn into an annoyance to others. No need to despair, though. The "gimmes" do have a cure.
Say "no" and then stay firm. Young kids have trouble understanding the idea of ownership. They might see something they like or want and then think they can have it just because it's there. Once you say "no," be prepared for crying, complaining or guilt trips. Stand your ground and take your child away if necessary. He'll eventually get the message.
Control your own behavior. If you take your child shopping, don't touch and handle everything you see. You're sending the signal that grabbing stuff is okay, even if you have no intention of buying it. Instead, shop with a list and tell your child you're only buying things on the list. When you want to go window shopping and touch all the pretty dresses you see, leave your child at home.
Explain to your child he can't grab things without asking permission first. It's tempting for a toddler to go into somebody else's house and grab everything he likes and doesn't have. When this happens, take the item away and tell your child "That's not yours." Explain that he wouldn't like somebody going into his room and taking his toys without asking him first. This might be a hard concept to grasp for young toddlers, so keep repeating the concept as many times as necessary.
Strike a bargain with your child -- every time something new comes into the house, something else must be donated to charity. The item your child gives away must be of similar value, so if he wants a new toy truck, he must give away another truck or game. Tell your child you will go home and choose what to give away before you can buy something new. In many cases, the child will forget about the item once you're back home. If he doesn't, you can still use the experience to address the importance of controlling temptation and waiting until the right moment to buy something.
Remove temptation around the house. If your child is grabbing things from your own home, simply move objects to a height he can't reach. Otherwise, you'll have to follow your child around repeating, "No, don't touch that," all day long. Install child locks in cabinet doors so he can't grab what's inside and keep low-level counters and tables clear of attractive objects.