
Pointers
Of course, part of the fun of playing games or using new apps lies in discovering new items in the new world we just stepped into. It can be part of the game play to discover new items. If that is the case, do not give too many pointers to the user as to where he needs to look. It is up to him to figure it all out.
However, in other cases, this is not desired at all. Imagine that you are playing a game, and you need to guide an avatar around the room. You can do this by looking at the avatar. In order to do that, you need to find it first. In that case, I would suggest that you use visual pointers to help the user find the avatar.
The user is probably used to having a pointer in the center of the screen. After all, this is the first thing the user sees when he turns on the device for the first time--a tiny white dot in the middle of his view that turns into a circle when the device sees his finger. Use this knowledge in your app, but enhance it.
You can use several icons or styles to do this. You can add a small arrow next to the dot, pointing in the direction the user needs to look, or you can make a colored disc that shows where the action is:

The size and presence of the icon depend on how important it is for the user to look in that direction. If you are creating an app in which there are several things that might be of interest for the user happening at once, use tiny markers around your cursor, which indicate that the user might be interested in looking in that direction. If the app is at a point where the user needs to do something in order to do anything at all, a big flashy sign saying LOOK HERE might be a better solution. It all depends on the situation, but ensure that the way you use this is proportional to the importance finding these objects has to the user.