In the bowl of a 7- or 8 cup food processor, add the peaches, agave nectar or honey, yogurt and lemon juice.
Process until the frozen yogurt is smooth and thick, about 5-6 minutes.
Serve immediately if you don't mind really soft frozen yogurt, otherwise, scrape the mixture into a tupperware-type container and freeze for 20 minutes (or up to a month if well-covered).
Notes
Doubling: this recipe easily doubles but you'll need a really large food processor (it worked well in my 14-cup food processor). Serving: also, you can serve it immediately but it's pretty soft. It firms up great after about 20-30 minutes. Food Processor/Blender: you need a food processor for the frozen yogurt but it's probably worth a try to make it in a high-powered blender (like Blendtec or Vitamix) since they can usually make ice cream type desserts quite well.Fruit:we've tried this with strawberries and blueberries, too, although peach continues to be our favorite (the creamiest of all of them). I think mango would be fantastic also.