does anyone rent their gear to others?

I'm thinking of getting a jib and wondering if it's worth getting something a little more solid and offering to other local production companies to rent? perhaps the same with a good dolly system etc

Not many insurance companies will cover your gear while it's rented to someone else - that person would need to supply their own insurance to cover it. That's one issue that I know of. I've rented some of my gear out in the past, but I had one major issue that came up, and even though everything that was broken ended up getting paid for, I decided to stop doing it.

My brother-in-law runs a more consumer-geared rental company and seems to do fine, but you have to price in your liabilities - repairs, loss, theft, etc.