Product Test: Drain Stopper
We bought the Snug Plug Drain Stopper at Bed, Bath and Beyond for 3.99.
It claims to fit in just about any sink drain and it just sets right in there. Our tester, Lindsay tried it out and thought it did a good job. You just push it down to stop the water from flowing and push it again to drain the sink.
Easy, cheap and it works. The Drain Stopper was given two thumbs up by our tester.