Check this thing out http://www.nationalcrane.com/MCG_POT_AM/Products/EN/igoma13.asp I wounder what it cost? It would be great on new home and remolding sites that have tight accsess. I wouder if there is a market to rent this out as equipment and operator by the day / week/ month to other contractors.
self erecting cranes I've seen one of those in use around here, they set it up in the middle of a pre-fab building and used it for everything, and then on a office type building that was 3 stories high, the operator has a remote that goes around his waste and that's it, they're kinda cool to look at and watch, I'd say that if there was buildings going up then people would probably be interested in renting one.
Self-erecting crane We took at look at the Igo 50 up close. It was impressive. http://www.constructionequipment.com/article/CA6386883.html
I have used them on a couple of larger jobs. they are worth their weight in GOLD. basically there a user friendly tower crane. Setup and tear down in less than a day. remotes put you RIGHT at the work not staring down at it. their biggest current down fall is they were designed to the mobile crane standards but are being held by osha as full fledged tower cranes. That means going through all the red tape associated with getting tower crane permits and approved site setup plans and all the other BS. when I used them they were UNDER osha's radar and I had them up and working in less than a day. Ran them for several months till the job was done and had them down and off the job in less than 8 hours.