I have an ethernet cable that I need to connect into two different devices (xbox and pc) this ethernet cable is already coming out of one router can I use this cable to power another router?

You don't want to do that. If you have no more ports on your router, then you can daisy chain a switch to the router to add more ports.

Nah the problem is that the ethernet cable I have is 250 feet of wire and it was a pain to wire so I was trying to avoid having to wire another one thanks though

You can but your mileage may vary. If you can string another cable you're better off. But if you have no other option then you can split the cable and run two connections over a single Cat5 cable. This is not a typical way of doing connections and is generally not recommended but it does still work. You can either buy dedicated splitters or make your own if you have some RJ45 plugs and crimper. You take pins 1236 and dedicate those to one jack and 4578 to the other. Basically you take the orange/green pain for one connection and the blue/brown pair to another as follows:


1 White Orange
2 Orange
3 White Green
4 Blue
5 White Blue
6 Green
7 White Brown
8 Brown

The cable has the above wires... the RJ45 connector also has the same ones. For the first connection take the orange/green pair and connect them as normal leaving out the blue/brown wires. For the 2nd connection take the blue/brown wires and connect them to the same positions as the first. i.e. 4578 will connect to 1236 on the RJ45 ends.

Worse case scenario you may have to configure your end devices to run at 10Mbps but this generally will work for 100Mbps especially since you're not near the 100 meter mark. I have this same scenario in my house.

Here's an example of a commercial splitter:

1-to-2 Female-Female RJ45 Network Cable Spliter Coupler (http://www.sourcinggate.com/1-to-2-female-female-rj45-network-cable-spliter-coupler-p-8217.html)