Desktop/GUI Java is pants, and deserves the hatred.
Server-based Java is actually capable of being very fast and good and stuff, but it does rely on the developers knowing what they're doing, and can require appropriate tuning to get the best out of it.
People use it because it came along and attracted people away from C++ and then nothing else has come along to replace it, except for C#.NET which is Microsoft.
(Java the language is a horrible over-engineered pile of shite, which is why there are so many alernative languages popping up which use the Java platform, but don't require using the horrible Java syntax.)
I had already done that (only i gave it EVEN MOARRR then pete suggested) - The server tells you to do it if you don't do it (message thing comes up saying "NOT ENOUG RAMOMG!! DO THIS [command] TO MAKE ME HAPPY")
You miss understand. My PC is the server, I use my laptop for mining. I prefer mining from the sofa :C
And I think it might not be as simple as I thought - I'm think that cable modems still need cross-over cables, so plugging my patch lead from my pc into the modem probably wont work mebbe.
I just installed Minecraft and it's actually causing my computer to shut down every few minutes :( I'm not too fussed as I'm sure it'll work on my Macbook, so not a waste of money, but I would like it to work on here :C