While we were one our trip to the Bay Sadie seemed to overcome her desire to throw her sippy cup onto the floor. We were in a restaurant and when she put it down on the table Paul made a big deal about how good she was being and told her that she was being a very good girl. After that she spent the meal very proudly flinging her cup onto the table (a bit forcefully). Most of the time it landed right side up. It worked pretty well because she was in a restaurant high chair, which was pushed right up to the table, rather than in a regular high chair, that has it's own tray and sits back from the table.
Now that we are home Sadie still remembers the little lesson that she learned. She still wants to put her cup down on the table. The only problem is, she doesn't want to set it on her tray in front of her. She wants to put it on the big table, which is one the other side of the tray, making it quite a ways away. Sadie has found that if she tosses her cup she can get it onto the table (one way or another). At least she hasn't tried it with any of her straw cups yet, just the sippies.