Poker Programs helpful or nonsense?

[srm80]

I have been wanting to find another way to improve my game other than reading and browsing websites, and heard there were poker programs that simulate live play. you can set the level of your opponents, how loose or tight or tricky they are, set the game for short-handed or a full table. I have seen these programs advertised in a Caro book and some others, one is called Turbo Texas Hold Em for Windows. Has anyone used a program like this to improve their play or to practice against tougher competition before actually moving up a level? Are these programs actually helpful or just a waste of money?