I've explored this idea before. There are a few problems, although not necessarily fatal ones. Major categories are engineering and sales. Engineering, you hav

I've explored this idea before. There are a few problems, although not necessarily fatal ones. Major categories are engineering and sales. Engineering, you have to build the thing. The best solution I found was bistable mechanical relays. A solid-state approach will have limited current handling and a lot of waste heat, while a monostable relay will consume power continuously in one state. The catch is that the fabrication cost is nontrivial. You'll also want some various things like current meters and a programmable controller. You also need to pay close attention to usability and ensuring that it behaves intuitively. Safety needs to be adequately addressed, probably including certifications despite the significant time and cost. The key sales obstacle is that the end result is going to be expensive compared to a passive power strip. You'll want to constrain the fabrication cost as much as possible while still affording the most important features. It may be worthwhile to go with basic and premium versions, although this significantly increases your development, certification, and production costs. I haven't had the time or capital to do this, but I'd be glad to see you pull it off. I was thinking about it in the first place as a practical way to reduce my electric bill.