I pick mine just before the first killing freeze or frost, place them on cardboard or something similar navel side down and let them ripen in a cool (not bright) place. I often have fresh garden tomatoes at Christmas, though not ripened on the vine.

Slightly off of the original topic, but I'm hoping to take cuttings from a cherry tomato that was a volunteer in an ornamental grass flat. I have no idea of the variety, but it has the most tender sweet skin...almost can't harvest without crushing them. Anyone overwinter tomato cuttings?