When it comes to the LSAT, I have to constantly re-read as I suffer from sever anxiety. This slows me down quite a bit.
I was actually wanting it for the LR section as well. When I took the Sep test I didn't finish the LR section because I kept having to reread.
I'm using the Eye-Q computer program (google it). Personally, it's helped me out a lot because I used to have trouble finishing RC and LR in time. But be careful, with any speed-reading program you have to focus on actually remembering what you read (not just blazing through words as fast as you can). What makes it even tougher for the LSAT is that you also have to understand argument strucutre while under time constraints. Your speed for doing this will rise, though, just not as fast as your WPM.