A little script from a job with a HUGE environment (basically a city made to scale in cm units. Good grief). Just to help get things moving more quickly I threw this together. The cameras layouts were set up and we had to throw the characters into the scene, but when we referenced them, they came in at the origin which might be 10's of thousands of units away from the camera position.
So to ballpark things I made this script. . . Really simple actually, select your camera, enter a distance and hit "create Locator" which will create a locator at the specified distance in front of the camera. (Or you could make your own, though that kind of defeats the purpose) You can then move the locator around if you're not happy with the distance or undo and try again with a new distance.
Not a big deal, just something to ease the pain of trying to pull things around a scene that's way too big for it own good :)
HERE is the script if you want to have a go. (rt click and save as)