"What is your measurable evidence that the earth is young?"

Evidence from lack of minerals
There's the silt on the sea floor, for instance. If the earth was millions of years old like you say, the silt on the ocean floor should be much, much thicker than it is, because of the rate it collects from rivers and such.

Evidence from the presence of earth's magnetic field
The earth's magnetic field is deteriorating rapidly, and if the earth really is billions of years old, as Evolutionists claim, then there would be no magnetic field at all by now!

Evidence from the earth and moon
The moon and the earth must be young or they could not exist today. The moon is gradually pulling away from the earth, but it also could never have been too close to the earth (the Roche limit). The present recession rate of the moon, multiplied by millions of years, would result in the moon being extremely farther from the earth than it really is. Also, the earth's shape is round. If it were really millions of years old, and the moon were closer to it to begin with (as evolution requires), then the earth would be kind of oval--bent out of shape. But it's not!
There are tons of different problems for evolutionists in this thing....in the words of one of them:
"the time scale of the earth-moon system still presents a major problem." (Louis Slichter, evolutionary scientist)

(this is more of a side note), the term 'young earth' should be used by evolutionists; Because evolution says that the universe is older than the earth, so in comparison to the universe, the earth is 'young'. In Biblical history, the Bible was one of the very first things created ("In the beginning, God created the heavens and the earth", Genesis 1:1), so we should consider the earth to be the oldest creation in existence. So really, we have our terms backwards, but since 'young earth'=literal Bible history and 'old earth'=evolutionary worldview are general terms that people recognize as identifying the opposing worldviews, they can still be used, even if they aren't really consistent. :)

Evidence from agriculture
Evolution says that man split from the apes about 3 to 8 million years ago. About a hundred thousand years ago, man was unable to farm. They hunted and gathered for their food, just like their primate cousins. Then, about ten thousand years ago man learned to plant seeds and farm (the latter claim is based on archeological evidence).

So here's the bottom line of this evolutionary assumption. You're trying to tell me that man lived for ninety hundred years doing nothing but scavenging for food?! It doesn't make sense. Doesn't it seem more likely that someone would go "hey, look--food, he grow from seed! Ogga, lookie!" (pardon the play-acting)-? I mean, NINETY HUNDRED years without knowledge of farming.

Evidence from archaeology and historical documentation
Archaeology has found lots and lots of sites and show the intelligence of these early peoples. For example, they constructed huge monuments, drew amazing cave paintings, and kept records of lunar cycles (these are the people didn't know how to farm, remember. Instead of fitting with the rather disjointed evolutionary interpretation, it fits beautifully with the Bible, that man was smart from the start.
Another question: If evolution is true, then when did man begin to keep a record of history? Evolutionists say that it was only 5,000 years ago. Does that sound logical to you? I mean, after all, if early man could do all these wonderful things like I listed a minute ago, then don't you think it'd occur to them to write it down?

Again....the facts fit the Biblical account.