I think the first thing that comes to mind, is getting rid of all the useless, abandoned buildings, and rebuilding/refurbishing them, then giving them a new purpose. It disgusts me when I drive into Troy and see a massive building unused, yet completely workable, and then right down the street a similar building being built for a new hotel =V
And also, if you do it right you could get rid of currency, but you'd have to totally rewrite just how we think about obtaining materials. In this day and age, a lot of people want the "biggest and best" think you can get. So if you made everything accessible for free, then everyone like that would have *the* biggest TV's and computers and houses, etc. People would have to overcome that and learn to really limit themselves. And a lot of people just wouldn't be able to do that. Perhaps in that society, I wouldn't be able to have my 42" TV. As much as I know I don't *need* it, I also do really enjoy having it, since it provides as much use as it does.
But how to make that sort of society work is really spinning off topic ><