Well, i was a little bit interested in it, plus a little bored, so I wrote a program that will help take down something like a server you hate. When run, it will move it's self to the system directory, and make a registry key to launch on startup. When the system's clock reaches a certain day (I can change it to be more accurate if needed) It will start the attack. It's pretty basic, with a bit of mixing up what it sends, but it will no doubt get the job done if you wish to take down something small like a server. Taking down a website is many times harder, but still achievable by this, and due to the legality I won't take part in it.
EDIT: if this isn't clear to people, the difference between DoS (Denial of service) and DDOS (Distributed Denial of Service) is that DDoS required many people to do it. What this does is unsuspectingly causes the victim to take part in a large Denial of Service attack.
If you wish to get hold of this, post in here just to acknowledge the post, but also contact me on my MSN which is in my profile or PM me I just won't post anything in here because i don't want random people ddosing people.