Instead of 1 egg, you can use...
• 1 tbsp gram (chick pea) or soya flour and 1 tbsp water
• 1 tbsp arrowroot, 1 tbsp soya flour and 2 tbsp water
• 2 tbsp flour, ½ tbsp shortening, ½ tsp baking powder and 2 tsp water
• 50g tofu blended with the liquid portion of the recipe
• ½ large banana, mashed

You should be able to use half a banana per egg.