A couple weeks back I built a simple web app in javascript that I use as a read-only bit coin wallet. After using it for a couple weeks I am fairly satisfied with it and thought I would share it. Maybe someone here will find it useful. You can choose to get current prices from either mtgox or bitstamp, you can display your wallets value in 19 currencies and can display your btc in either ubtc, mbtc or btc. All of the public addresses you enter are stored in your browsers local storage. The wallets value is updated about once every 10 seconds and once every 5 minutes your addresses are checked for incoming/outgoing transactions and it will notify you if it discovers activity. Just to clarify the only data it requires from you are the PUBLIC addresses that you wish to monitor:
https://bitmagi.com
