Sim in a Box
Building a proper sim takes time, a whole lot of time, unless you are a master builder like Lordlfy. But if you're just that average kind of bloke who barely scraped together the money to buy a complete sim and you want to make money from renting out property, you'll want it up and running smooth and (especially) fast.
So your sim is in and you want to rent out as soon as possible, since you don't have Anshe's wallet to be able to leave it unused for a year or so. Monthly tiers can be a killer to many starters. For those the Sim in a Box might be a very good solution that can jumpstart your sim.
The Things to Do group got a demo today of how to build a sim in 5 minutes. Well, it works.
Though I'm not really charmed. I like mine with a little more labour-of-love touch than what this instant-sim HUD does.
However, from a technical point of view, I think this is a big step forward. Predefine content and make it rapidly deployable, auto rezzing your inventory might be huge timesavers.