About a year ago, I was reading through an old chess magazine and found a half forgotten idea that has helped me a lot. I set up my board and turn on my Chessmaster program to a high competitive level. As we move past the book openings and into the middlegame the machine begins to gain the upper hand, I then use the take back move feature, going back 3-4 moves, then try another line of play, then another, etc. until I find a move strong enough to keep the machine and I roughly level, and writing down these lines as I go. This "learn as you play" method has sharpened my tactical skill and forced me to consider things I've not seen before. Some would argue that the machine doesn't play like a human, so this exercise is flawed, however I cannot argue with the results, after doing this 9 months for a few hours a week, I'm now solidly in 1600 - 1700 territory, after 3 years in the low 1400's! Used correctly, the machine can be your friend.