Place each chicken breast half between two pieces of plastic wrap. Using the flat side of a meat mallet, pound chicken lightly to 1/4- to 1/2-inch thickness. Remove plastic wrap. Cut pounded chicken breast halves lengthwise into 1-inch strips. Place the chicken strips in a glass or ceramic bowl.

In a spice grinder, combine allspice, thyme, peppercorns, nutmeg, and cinnamon. Grind mixture to a fine powder. (If some large pieces remain, pass mixture through a fine-mesh sieve; discard large pieces). Transfer mixture to a food processor. Add brown sugar, garlic, shallots, and Scotch bonnet pepper. Process until coarsely ground. Add rum; process mixture to paste consistency.

Add spice paste to chicken strips; gently toss to coat. Cover and chill for 1 to 24 hours, tossing occasionally.

Wearing plastic gloves*, loosely thread chicken accordion-style onto twelve 8- to 10-inch skewers.** For a charcoal grill, grill skewers on the greased rack of an uncovered grill directly over medium coals for 8 to 10 minutes or until chicken is no longer pink, turning once. (For a gas grill, preheat grill. Reduce heat to medium. Place skewers on greased grill rack over heat. Cover; grill as above.) Serve chicken with lime wedges. Makes 6 servings.

*Note: Because hot chile peppers contain volatile oils that can burn your skin and eyes, avoid direct contact with chiles as much as possible. When working with chile peppers, wear plastic or rubber gloves. If your bare hands do touch the chile peppers, wash your hands well with soap and water.

**If using wooden skewers, soak them in water for at least 1 hour before grilling.