Answers:
A switch is the correct answer. These are immensely inexpensive and can be found in most department supply stores.
Use an everyday frequent lattice switch. Like somewhere contained by the "middle", this style once you catch to the switch the "meters" reset again to 0 and you can dance another 100 meters.
Fiber optic would be expensive, but you can move about much further than CAT 5 or 6.
You can put in a hub or switch and that will tolerate you start adjectives over at nothing meters. I certainly did this several years ago previously wireless become middle-of-the-road. I have to run cable across an entire shopping shopping precinct, so I lately put within a switch every 100 meters.
Some extenders, not cheap.
You weren't very specific so i can individual assume that you want to do this to run ethernet to a barn/garage building away from your home.
In this overnight case, you will enjoy to build your own cable, explicitly, buy a bulk roll
http://www.ramelectronics.net/html/cat5_...
and buy some RJ45 plugs
http://www.ramelectronics.net/html/cat5_... and chain them yourself.