Recent systematic reviews show that stretching before exercise neither prevents soreness nor injury. Regarding soreness, a Cochrane Review looked at 10 studies in young, healthy adults and found no significant difference in muscle soreness up to three days post-exercise in those who stretched before working out and those who did not. Similarly, another Cochrane group reviewed strategies for hamstring injury prevention and noted no difference in injury rates between those who did specific hamstring strengthening exercises or stretching and those who did neither. There is also some evidence that pre-exercise stretching may result in decreased muscle strength and power.
It appears that a few minutes of warm-up focusing on the same movements that will occur during the period of exercise is sufficient. So please stop with the ritualistic stretching and get on with the exercising.