Put the meat in a sealed plastic bag, place in a bowl in the sink, fill with cold tapwater, then set the tap running in a thin stream with the water overflowing the sides of the bowl.
The moving water will safely thaw the meat through convection.
Make sure you get as much air out of the plastic bag as you can.
You might need to put some weight on it in the bowl to keep it submerged in the water.
cooking.stackexchange.com/users/2643/ThinkingCook
If you're really in a hurry then you can't beat the microwave.
It might defrost a little unevenly, but assuming you plan to brown it or something afterward, then that will take care of evening it out.
The microwave is perfectly safe; the key point about food safety here is not allowing the meat to sit in the "danger zone" (basically more than a few degrees above freezing) for a very long time, and if it's only defrosting for 5-10 minutes in the microwave then that's perfectly safe.
Just make sure you cook it immediately afterward.
cooking.stackexchange.com/users/41/Aaronut
Just to be aware, a lot of people worry excessively on the safety issue.
Restaurant rules (at least here in Seattle) say that food coming out of <40-degree storage must be back in the cool storage and back down to <40 degrees within ... six hours.
Seems a long time to me but that's the rule.
This isn't really an issue for this thread cause ahsteele is after quick defrost anyway.
But just sayin'...
cooking.stackexchange.com/users/None/
I've started using a new technique for defrosting without doing so unevenly.
It takes a lot more time and patience than just hitting defrost and coming back 10 minutes later to a partially cooked plate of raw shrimp or fish (would work for ground beef as well.)
What I do is to run the microwave on defrost for about half the time it would take for a "normal" microwave defrost (where the edges of the fish and/or some shrimp are pink in spots.)
Then I run the microwave for about 20 minutes at 10% and check on it periodically until it's defrosted.
I've also done the ziploc bag trick, but it sometimes leaks and it's really hard to submerge it.
Putting it in front of an oscillating fan can work as well.
cooking.stackexchange.com/users/2690/Jeff Axelrod
The quickest way is to defrost is in the microwave, although it may not defrost evenly and some may 'cook' slightly.
Defrosting meat quickly usually means you lose moisture too.
If you are planning on using the beef straight away I wouldn't worry about the safety issue as long as you cook it through.
cooking.stackexchange.com/users/2757/LittleDishy
This works only in the winter months: Get home from work.
Turn on heater for cold house.
Set frozen ground beef on floor vent Turn in 10 mins.
Total time 20, fully thawed.
My house drops ten degrees during the day
so the time it takes to get to 70 is how long it takes to thaw my dinner.
cooking.stackexchange.com/users/15678/Chris
Laying the meat on a surface that conducts heat works well too.
I find that putting frozen meat directly on a granite countertop or in a copper sink (with minimal wrapping) will thaw it much more quickly than a wooden cutting board or dishes.
cooking.stackexchange.com/users/29838/Greg Nickoloff
Since reading the answers to my question about  defrosting meat on the counter  I've been good about giving my meat time to defrost in the refrigerator. However, my plans for tonight have changed and I'd like to defrost some ground beef that is completely frozen for dinner this evening. What are my options to do so quickly and safely?
I need to quickly and safely thaw frozen ground beef, what are my options?
cooking.stackexchange.com
<food-safety><defrosting><ground-beef>
cooking.stackexchange.com/questions/7779
cooking.stackexchange.com/users/809/ahsteele
The quickest way is in the microwave, although this may not defrost evenly and may cook some of the meat slightly.You can also put the meat in a sealed plastic bag in a bowl, and run a thin stream of cold water over it, allowing the water to overflow over the sides of the bowl. Laying the meat on a surface that conducts heat well also works well. The microwave is the fastest and easiest option. You can also try submerging it in a bowl of warm water.
Put the meat in a plastic bag in a bowl of water. The microwave is the quickest option. Try laying it on a warm surface.