Radar gun measures up!
I bought this after watching a young man use it in his neighborhood. Living in a "planned" community in Washington state, we have the problem of speeders and the paid security guards really can do nothing. People who are stopped simply complain to the managers, or just use their really foul mouths, and ignore the tickets. Since I have been using this, in full view of any approaching vehicles, people SLOW DOWN, at least until they are out of my view. It's an inexpensive and useful tool to slow speeders down! I'm sure glad I saw that television story about this radar gun!!

Real Radar
I bought this item to measure the speed of nitro cars. It works well but is not very high powered so you must be close when measuring. This can lead to some excitement reading speed then dodging a 10 lb car travelling at 40 plus MPH.

It is well constructed very unusual and reasonably priced for a very sophisticated toy. I don't know how long the novelty will last for kids but for me it has been useful.

A little harder than it looks
This is a cool toy, but it is harder to use than it looks. You have to aim it just right to get a good reading, so little ones can get frustrated. My son is only 6, so maybe this toy would be perfect for a kid a bit older.

Good cheap radar gun!
I bought this for my 4 year old and he had fun with it for the first two or three days.

In the end, I use it to gauge how fast things are going and we talk about relative velocity and going fast and the dangers of such.

I also use it to assist in slowing traffic down on our residential street. As soon as drivers see this thing, they think its local police enforcing traffic and they do slow down. Using Pavlov's method, over time, you can condition regular violators to move at the posted 25mph or below.

Great fun. Tennis serves, biking, nitro rc cars, etc... The uses are endless.

Excellent toy.
Every dad who loved hot wheels as a kid should buy one of these radar guns (as a gift for his child, of course). It adds a new element of fun to racing the cars down a track, and can even be educational. My daughter now knows for sure which of her Hot Wheels is fastest.
It is simple to use, and can even be used on other moving objects such as bikes and real cars. I can't believe that this technology is available at such a low price. We have only had it for a short time, so I cannot speak to durability. It does seem to be well constructed, though.