Popular science magazine had a small article about a man that created something like a mecha with hydralics and wood. I believe it's possible, but not really plausible. I think, given with the current rate of technological growth in just the last 50 years, we might be able to do it within the next 25 or so years. But I also believe that it's not effecient enough to be of any real use. Not unless you can make them almost exactly like those in the anime, fully equiped with weapons and such. Personally, I think focusing on something like an 'Ironman' suit would be much more effective. Unfortunately, that's even less feasible because of the amount of technology that would be needed to power it. The technology just doesn't exist right now.