Eckhart Tolle is only a recent guy to talk about being present. Check him out on Oprah. They really did a nice job of presenting material to people that may be new to this kind of stuff.
An earlier guy who talked about being present is Bhagwan Shree Rajneesh. In his book, Yoga: The Science of the Soul, vol 1, he says, "The present is almost always a hell. You can prolong it only because of the hope that you have projected into the future. You can live today because of the tomorrow...You cannot think anything else than the past. Future is nothing but past projected again, and both are not. The present is, but you are never in the present...Your mind is a drug. It is against that which is...You can go on doing asanas,postures; that is not yoga. Yoga is an inward turning. It is a total about-turn. When you are not moving into the future, not moving toward the past, then you start moving within yourself--because your being is here and now, it is not in the future. You are present here and now, you can enter this reality. But the mind has to be here." And he goes on.
That whole section reminds me of a part of the Introduction to the Landmark Forum, the part where there's what you know and what you don't know and then there's the what you don't know you don't know, (click on the section called "see it in action" and then the first guy in the upper left box), which is where real yoga is happening. The being present now, entering a reality is like the part of the Introduction where you can create a possibility that impacts you NOW, not like a hope or a wish or a dream, but like something that's possible right now.
And Eckhart spoke about that on last night's webcast with Oprah - how any goal that you have, for it to be a good one, is basically something that's already present in your life because it's there, you've created it, and you're just bringing it forth. Allowing it to be manifest.
It's fun when it gets a bit woo-woo. Reminds me of my living in the ashram days. Otherwise I can go for ages without getting a bit woo-woo.