Mix all marinade ingredients in a small bowl.
Place cleaned shrimp in a zipper storage/freezer bag. Pour marinade over shrimp, seal bag and invert bag a couple of times to coat shrimp. Place in refrigerator for 30 minutes (do not marinate any longer than 40 minutes or the acid will "cook" the shrimp and make them rubbery)
If using bamboo skewers, soak them in warm water for 30 minutes prior to cooking.
Preheat grill to high heat. Skewer shrimp (if desired) otherwise use a grill basket. I prefer skewering as they are easier to turn, cook and serve. Sprinkle with salt and pepper to taste, if desired (about 1 tsp salt, 1/2 tsp pepper in total)--always salt immediately before cooking!
You can discard the marinade -OR- place it in a small saucepan, boil and reduce it for a delicious dipping sauce.
Cook about 5 minutes each side, or until shrimp are pink (but you can still see some translucency in the middle). Do not overcook!
Sprinkle more roughly chopped cilantro over shrimp before serving, if desired.
Shrimp may also be broiled in a conventional broiler.
NOTE: I had extra-large shrimp, so I skewered 4 shrimp per bamboo skewer. To prevent bottom part of skewers from burning and becoming too hot to handle, I use a strip of aluminum foil to shield them from the heat