I've been roasting my own coffee a few years and I really love it as a fun, backyard activity that most people don't know is possible. Every time we've roasted, we've introduced new people to the process who made time in their busy schedules because they just had to see it in action! This method is great because it's a lot less fickle than other roasters and there are still several jobs for people to rotate through, making this a nice activity for a group of 3+.
I picked up a Whirley Pop Popcorn Maker for $1 at a yard sale after hearing it was a good option for roasting but it produced too much smoke to use indoors in my apartment. After losing access to the space we've been roasting on a charcoal grill, I went back to the Whirley Pop and found a willing co-roaster with a backyard and grill that we could use and we were in business!
This couldn't have been easier. This process was a lot less setup than the charcoal roaster and the resulting coffee is mighty tasty. I use most for espresso and it produces a great crema. (I'm currently sipping on an latte made from home roasted beans! Mmmm.)