I've made a simple converter for the main ether denominations: wei, finney, szabo, etc. It's useful to learn them or for quick reference.
It also convert from/to satoshi, bit, bitcoin and USD$, based on the 1 BTC = 2000 ETH pre-sale. I know that exchange rate is somewhat arbitrary for now, but someday they'll connect.. The input value and unit get encoded in the URL hash to save or share.http://ether.fund/tool/converter