Billiebob is correct. There are some things to think about with tongue length. The shorter the tongue is the quicker it will be to turn while backing up, too short and it turns too quick and it is a pain to back up. Longer tongues will respond slower and can be easier to back up, but require wider swing. Longer tongues will track better going down the road, shorter will follow a lot closer to the tow vehicles tracks, the long tongue will want to cut the corner a lot more.
There are advantages to both a long and a short tongue. If you are scooting around town a lot, a short tongue is great, spend a lot of time on the highway and the longer tongue is smoother and more stable. Short tongues get "twichy" at high speeds.
This assumes all else being equal, ie. that the weight distribution is correct. If you get the weight wrong and any trailer will handle really badly.
I watch a lot of offroad videos of 4 wheelers in Australia. They make some real nice off road camper trailers and all of them have really long tongues. The only down side to this seems to be the breakover angle really suffers. A short tongue would have a much better breakover angle and would not get hung up on as much stuff.
In the end both long and short have their place, you have to decide what you want out of it, then get the weight distribution correct and you will have a great trailer. I have seen people shorten the tongue for no other reason than to make it fit in the garage, it is all up to you and your needs/wants.
