If redesigned for actual usefulness, they might look cool in combination with paper wallets
Warning: None of these codes are for wallets, they are just the receiving addresses. Feel free to send some money there
One BTC goes to the author of Cryptonomicon, one of probable inspirations for bitcoin
On the back is a nondescript graphics card
Three BTC (the "fake" bill) features lulzsec. I actually discovered bitcoin because their website accepted donations in BTC
Their lulzboat is on the back
Eight bits goes to pacman because he got into our homes in eight bits... or something
On the back is the 256-th level split screen bug, aka the 9th wonder of the world
Ten bits features the mighty alpaca, source of all your survival socks
On the back is the Machu Picchu, the main feature of alpaca's home, Peru
100btc features the last known image of bitcoin's creator Satoshi Nakamoto. I know that the smallest unit of BTC is called a "Satoshi", but he still deserves to be on a bill
And the back features the silk route - a symbol of togetherness through trade
Who/what would you like to see on bitcoin bills? How would you design bitcoin bills (or paper wallets) to look cool and be useful?