Slice cucumber lengthwise into 8 thin slices. (Use a kitchen mandolin if you have one, but be careful, they're VERY sharp!)
Peel carrot and cut into matchsticks.
Place a small amount of cream cheese onto the end of each cucumber slice. Add some carrot sticks and a few raisins (not too much or it will make it difficult to roll up).
Roll up cucumber, tucking in anything that falls out. You can place another small dollop of cream cheese on the end to help keep the sushi rolls together; secure with toothpicks if needed.