Do casinos that have prizes like cell phones, tablets give prizes? Do they send you to the country? Has anyone experience this?

Yes. Speaking from my own experience, they give these prizes including luxurious trips abroad, but there's one major problem about it. The casinos are often forced by the licensing authority to offer compensations for these trips or prizes. For example, you can win the new iPhone, the casino promotes the competition for the iPhone, but when you win it, they often have to offer you the iPhone or financial compensation, which would be maybe 1200$ or you win a trip to Las Vegas, but you are allowed to choose 10,000$ compensation.

Most of the winners (I would say over 90%) take the money instead of the prize. It's kind of better for the casino, because they don't need to arrange the trip for the winner or order the prize and send it to the foreign countries across the World. They just add cash on your casino account, which you can withdraw immediately.

I know of casinos that give away Harley Davidson, cash prizes , TV etc

Your comment seems important to me. I never took any of these promotions, precisely because I already took it for granted that if I won an iPhone, for example, I couldn't withdraw it. Thanks for making it clear!

Anytime you see similar promotion, I suggest you to find and read terms and conditions of the specific promo. Good casinos should have the part about compensations or how the item will be delivered included in those terms.