How Long Should You Wait Before Moving On?

Typically men and women have different views on this subject as it sometimes seems men have a shorter recovery span than do women. After a break-up, especially one that resulted after a long-term relationship, women appear slower to move on than men... depending on the type of guys they are anyway. I've seen cases where not even a month later the guy already has another girl on his arm and the ex-girlfriend is outraged thinking he should have at least waited that entire month and I'm sure there are cases where the shoe is on the other foot, although, I myself don't know of any such cases, I'm certain it happens though. So, my question here is this; is there or should there be a certain amount of time waited before moving on to the next romantic encounter? My opinion is yes, especially if it was once again a long term relationship. You need time to heal and don't want to carry extra baggage into another relationship, although I guess that too is debatable depending on whether the next relationship is serious or just a fling to get you over that hump. I'd still suggest giving yourself at least a little time to be alone, at least a month and up to maybe six, before hopping in bed with someone else whether it's serious or not though as feelings can get hurt and mixed emotions may be felt and a whole bunch of confusion can be created from your instantaneous bed hopping. What is your take on this? Is there a certain amount of time you should wait before moving on? If you'd say yes, how long do you think you should wait?