I bought some 'rum baba' moulds the other day - just little 5" ring moulds. Filled with sponge mix, they made 5 little rings which we arranged into the olympic rings, i bought some colours for icing in blue,black,red, yellow and green and they looked fab! Didn't last long tho......
also thought i'd use my silicon ring mould (about 30cm across, uses about an 8-egg mix, will prob do a choc-and-vanilla marble mix)) - if I ice it in white and decorate with pearly beads and jelly-tots, it might look like a crown?
Am going to a Jubilee party so more 'themed' food ideas welcome!