What's a good way/practice/exercise I can use to improve my keyboard typing speed?

you just have to keep doing it over and over again you’ll see how fast you’ve gotten if you keep typing, so send some messages, reply to comments/messages and keep trying.
good luck :)

I grab any article from the paper or a magazine and practice with that….or I type out some letters to family… I also use an ergonomic keyboard and I find that helps for me…..just practice practice practice
you could also try an online site, here is one for you
http://www.davis.k12.ut.us/cjh/appliedtech/Business/Keyboarding/

Like I said to the other guy, open up word and write some random sentences

Several comments from when this question was asked yesterday might be helpful.

Emailing with friends or posting on sites that talk about things you are very interested in helps I think. When you have a lot to say about a subject you try to get all of your thoughts down and it kind of pressures you to go faster. Also, if you have never had a typing class I recommend the basics. I don’t type exactly how you are taught, but it helped to have the foundation. I still look at the keys somewhat and I type 45 words a minute.

There is a game called Typer Shark that might help. It feels like you are playing a game but you are really building your typing speed. You get your hands all in position on the home keys and the screen looks like an aquarium. Letters start hitting the top of the “water” and you have to type them before they hit the bottom. It starts slowly and just gets faster and faster.

If you are a “look at the keyboard” typist, you will not do real well. This game will teach your brain and hands to know where the keys are (if you want to win, I suppose) and then, when your eyes are on the screen instead of your keyboard, your speed will improve dramatically.