As far as Alcohol 120% goes: That is not a free piece of software. Sure it works for 30 days or so on a free trial, but after that it will no longer work.
SD4HIDE works for me too, but when the 30 days run out, I am going to have to spend money to buy me another piece of software if I want to play without the CD. Since I have the original CD's nothing is going to prevent me from playing either way, but I would love it if game producers would do the "do-you-REALLY-have-the-original-CD?" checks on installation of the game, or maybe with an activation process just like MS Windows. (Their Activation phoneline is completely automated.)
Its much more effective in combatting piracy, and after installation is done, and your installation has been verified/installed/activated/screened through various methods, then you can nicely put the install CD away and play the (insert bad word here) game without having to insert the (insert really bad word here) cd's every time.
Its a shame that we have to use "shady tactics" just to play without the freaking cd....