Combine a cup of milk with 3 eggs.
Whisk it up good.
Mix a cup of flour with a tablespoon of sugar and a teaspoon of salt.
Whisk it up good.
Lift your whisk up from the bowl. The drip should look something like this.

Add milk or flour to get it to that consistency.

In a cheap (thin) non-stick pan melt a tablespoon or two of butter.
Pour the melted butter into the batter and whisk it up good.
Get a nice clean paper towel and wipe up the butter that's in the pan.
Keep the buttery paper towel handy, you'll use it later.
Let the batter sit for an hour. If you can't wait it's not horrible.
Heat your pan back up to about medium heat.
Pour enough batter to cover about 1/4 of the pan.
Tilt the pan around until the batter spreads out.
Even distribution of the batter is more important than getting a pretty circle.
Shake it around and put it back on the heat.
Here's a video of it. (you need xvid or divx to play it)
After a couple of seconds the edges'll look like this:

When they start to pull away from the pan, you can flip them over.

Your first crepe probably won't turn out, so don't worry about that one.
If your crepe doesn't want to flip over, take a fork and gently run it across the pulled up edge of the crepe, then try to peel it off by turning the fork.
Here's a video of that.
Notice how the crepe had an even color all over the in that video? If you crepes start to look like that, take the buttery paper towel and rub the pan down.
Each crepe should only take about 45 seconds. When you're done, you should get something that looks like this:
If you have extra batter it can be kept in the fridge for a week if you aren't picky about freshness.
If you're really lazy, you can make extra batter, pour it into an old chocolate syrup bottle and dispense it from that.