Starting this conversation since I believe it could be very useful and informative.
What have you frozen - excluding meals/veg - to use for later ??
From Coolgran I have learnt that it is possible to freeze ripe bananas and use them in cakes - never knew that 
I can suggest freezing lemons, in slices or whole to use later.
Also freeze grated chocolate - top a cake or desert later.
Squeeze a lemon and freeze the juice in ice cube trays, also grate the skin and freeze.
Fresh herbs also freeze in ice cube trays for later.
Any more tips ??