I've grown them for the last 20 years. Easy to grow outdoors. The only pests are slugs who eat the ripe fruits as they fall to the ground when they get bigger - but staking will prevent that. In a good season you get more than you can handle and they keep well too.
In the kitchen you can make the true Mexican salsa but i often saute or stir fry them or use them in casseroles and stews. They look like green tomatoes but have a more lemony/sweet type of flavour.
PS I have a good recipe for tomatillo chutney!
Have a go - you won't be disappointed!