Mix the jelly crystals with the boiling water and stir until dissolved. Let cool a little then stir in the vodka. Pour the liquid into 4 small paper cups or other small containers. Chill until set, at least 2 hours.
Pour champagne into glasses. Break up the jelly with a fork, and pour into each glass of champagne. A little stir gives it some 'lava' action.
This worked really well as the opening drinks for my friends hen's party. I ended up roughly chopping about half the jelly and putting it all in a bowl and then just spooning it into each glass as needed. It holds its shape long enough to look good and lava lamp-y and then dissolves creating a tequila sunrise-type effect in the glass. Nice-thanks! - 28 Sep 2008