Place the cumin, peppercorns, coriander
seed, caraway seeds, and cloves in a
dry skillet. Place the skillet over medium
heat, moving it to keep seeds from burning,
until the seeds are aromatic, about 3
minutes. Transfer the seeds to a spice
grinder, and cool slightly. Pulse until finely
chopped but not powdery. Transfer
the mixture to a bowl, and stir in salt, garlic
powder, onion, and cilantro. Set the
spice mixture aside.
Peel shrimp, leaving the tail and the last
section of shell intact. Devein shrimp, and place in a bowl.
Heat a grill or grill pan over medium-high heat. Sprinkle spice mixture over the shrimp, and stir to coat. Grill the shrimp until opaque and cooked through, about 3 minutes on each side. Serve shrimp immediately with lime wedges.