There are regulations but there are ways to get around them as well. 

I have looked at Colorado Springs STR regulations. 

I’m familiar with the technology, but I’m not sure how it would translate to a real estate environment. 

Just becareful as once you "scale" this idea, I THINK you can run afoul of the Security and Exchange Commission (SEC) since it becomes a syndication or some sort of regulated investment product. 

In today's yield-compressed environment, they are out there but it's not as if they can be easily acquired without some sweat and hustle.

Navigating the Nashville STR market has been interesting so far due to the regulation and having to keep the zoning in mind.

Each island (key) has its own specific STR rules and regulations.

Owner/occupants also have the option to make their buildings "active" and use the large losses created by cost segregation and compliance with the Tangible Property Regulations against the business income.

Does anyone know the rules & regulations surrounding short term rentals in Douglas County, CO and if they are strict to enforce any such rules?   

It is a rare break in favor of individuals in an overly regulated state.