@Salo phil,
When second life first came out, just after it started getting popular, I was on it and had some land and managed apartment rentals. It is very time consuming but a very creative environment. Most of the users on it actually use it as their second life. It's a life within another world, virtual yet very very real.
For the experience of it, I'd recommend Second Life to try out. Who knows, you may like it and enjoy spending time there. There's actually many businesses that spawn off of Second Life and many people who make a living running businesses in Second Life. Truly an amazing thing and I'm surprised more people aren't on there.
I'm no longer on there because of the time factor. It is a neat place though. The site is SecondLife.com.