I have done a few LSD trips. The first one was really weird, the rest were with smaller doses and less intense. They've given me a couple of mildly interesting ideas, but for the most part I don't feel like I've really gotten anything useful out of them. (I keep thinking that given the reputation that the thing has, there has to be some way of getting more out of the experiences, but for a large part it feels like my mind gets temporarily dulled by the thing so that I can't really think or do anything interesting, and then I just get bored and start waiting for the trip to be over.)