One of our friends recently had a pool installed in his house and to protect his kids from drowning in the pool, he installed a vertical Magna Latch.
The concept for the Magna is cool because the latch sits about four feet off the ground and in order to remove it, the child needs to pull up on it. The Manga Latch is basically a lock powered by a powerful permenent magnet (never loses its power), so the gate snaps and is locked. Additionally, the lock can also be locked with a key, so it adds double protection.
Anyhow, we thought it was a clever device for those looking to secure their pool for the safety of their kids. The Magna Latch seems like a good way to keep them out.
Make sure you check with your local authorities for height measurement/requirements on swimming pool gates before actually buying one as those differ from county to county.