This is a lot like the Blue Lagoon, or the Blue Crush, although I think the Lime syrup/juice + regular vodka make it significantly different.

Pour 1/2 can lemon-lime soda into:
the following mixed/strained in a shaker with ice.
1 shot vodka
1 shot blue curacao
1/2 part rose's sweetened lime syrup
1/2 part regular unsweetened lime juice

Garnish with a wedge of lime and enjoy.