If anyone's interested, I've created an Ubuntu indicator that shows the current value of Ether (in USD/BTC) in the top menu bar. It also provides a drop-down showing details of the latest mined block.
It doesn't really do anything clever, but I find it a useful shortcut. I've tested it on my 14.04 setup, and I'm happy to help with any teething problems on other releases. It's also on GitHub, so feel free to steal it/fork it/make it better.https://github.com/RichHorrocks/ether-price-indicator