Stones of Remembrance

I came across a disheartening bit of research this week. It reported that within an hour after hearing a sermon, people forget up to ninety percent of it. I think there are obvious reasons and more subtle ones for such a phenomenon. 

We are forgetful by nature. God commands us to remember Him, His covenant and His Word. We have many biblical examples of what people should do in order to remember those things. As far as we are concerned, how do we do it effectively? How can we set up these proverbial stones of remembrance and actually return to them so that we can remember?