We've had this question already, but I want to narrow it down to already high-speed typists.
The original poster had hit a barrier of 75 WPM and wanted to increase his speed. I'm at a barrier where I can reliably type around 130, and I can sometimes hit 150, probably depending on the distribution of words in the text.
I feel that methods to increase speed from this high end to higher might be different than going from 30 to 60, or even 75 to 100. Anybody have any suggestions?
You need to start looking at the hardware... Try out different keyboards to get the best reactionary keyboard to your typing method. I find myself typing much faster on some keyboards even though they are identically sized with identical features...the key response times are slight different.
If you're trying to learn how to type your favorite language faster, may I suggest that you learn a better language?
When I typed dictation a lifetime ago, I could type over 120wpm on a dictaphone. When I type C I rarely exceed 90wpm, but when I write lisp, I don't even reach 50wpm.
The time you're spending typing isn't being spent thinking.
If you're trying to learn how to type copy more quickly, learning to read more quickly can help. I had great success using rapid serial visual presentation to increase my reading speed.