Here's a tip I just learned from an oil change jockey. Be forewarned though, I have not tried this nor verified that this tip works, nor am I aware of any pitfalls or hazards involved. Please be careful!
Let's suppose you just changed the oil a vehicle and found out the drain plug gasket is leaking and needs to be replaced. The problem is, you just added new oil to the engine, and don't have anything to catch the oil into for reuse. No problem. Just attach a shop vac suction hose to the oil fill and turn the vacuum on. When you remove the drain plug, the vacuum on the oil fill will prevent the oil from coming out the drain plug hole. This would enable the guy in the pit to remove the plug and replace the gasket with little muss or fuss.
This sounds good for someone in a position where this scenario would play out often enough to have a dedicated vacuum for this purpose. Like a high volume oil lube center. According to the person that provided this tip it's common practice where he works.