Right after seeing the post about preserved lemons in this thread, I was looking at people magazine and they had this recipe for a quick version:
step 1: wash and scrub 4 lemons under warm water. Quarter them, then cut each piece in half. Remove the seeds. Rub with 2 tablespoons fine sea salt and place in a small bowl for 2 hours.
step 2: rinse lemons under cold water. Add to a small saucepan with 2 tablespoons fine sea salt, 1/4 cup fresh lemon juice, and 1/2 cup water. Bring to a boil, then simmer until reduced by half and liquid is syrupy, 25 minutes.
step 3: remove from heat. Transfer to a sterilized non-reactive (glass or plastic) airtight container, and refrigerate overnight. They're ready to use the next day.