Put the lime juice, water, sugar, salt, and diced jalapenos into an 8 by 8-inch metal cake pan and stir until the sugar and salt are dissolved. Put the pan in the freezer and stir with a fork every half hour to break up the ice crystals. After 3 to 4 hours, depending on your freezer, the pan will be full of jalapeno ice flakes. Put your shot glasses in the freezer while this is going on.
To serve, fill a shot glass almost to the top with the jalapeno ice, top with an oyster, and garnish with some diced red pepper.