Bring a large pot of water to boil over high heat. Prepare an ice water bath by filling a large bowl of water with ice cubes. Slice a small "x" in the bottom of each peach. Blanch the peaches in boiling water for 1 minute. Remove with a slotted spoon and transfer to the ice water bath. When cool enough to handle, peel the peaches, then dice them.
In a large bowl, fold together the diced peaches, onion, bell pepper, jalepeño, mint, and lime juice. Season to taste with salt. Cover and refrigerate for 1 hour before serving.