I wanted to send a postcard for my good friend's birthday. With him being a programmer, I decided to tackle this one appropriately and created a cipher. He received it by post with hints of four colours, one for each row:
Each row is not just the same colour, but a progressing gradient, so assembling it is more fun :) The letters are on thick card, sliding in the row when you pull/push them.
This one says "All the best, and minimum amount of bugs..." after being assembled.