It would be great to have two jars be able to run simultaneously, so that tippers can use the jars to "vote" for their favorite teams, and also you can take your custom coins and fill your jars with them. i know that donation tickers can do something like this visually, but it's more sporting and fun to do it via a tip jar.
Think of cafes where you can tip for a choice. Britney vs Gaga or Alien vs Aliens -- tip your barista and vote for your favs at the same time! It encourages more tipping overall, and that's good foreveryone.