not sure if this has been done before:
a circuit design contest where all values have to be made up of either 1, 10, 100, 1K, 1M etc.
e.g. allowed values:
10p, 100p, 1n, 10n, 100n, 1u, 10u, 100u
1r, 10r, 100r, 1k, 10k, 100k, 1m, 10m
same goes for pots --> 1k, 10k ,100k ,1m