We recently ported our MacOS XBOX Live Friends widget to a browser-based version. It's been made publicly available for feedback as an "ALPHA" version. It's quite functional for an "ALPHA" giving users a short-term solution on Windows XP/Vista machines and the Apple iPhone/iPod Touch. Be sure to check it out and let us know what you think.
Click here for the 1337pwn XBOX Live Browser (ALPHA)
As with the MacOS widget, it will display the Gamertag, Score, Recent Game, and online status. It even updates status information after the widget is displayed. The underpinnings do require a modern browser that supports XMLHTTPRequest (ie. Internet Explorer, Firefox, Safari). It will not work with simplified browsers.
Let us know what you think. We're actively working to support other devices and improve the browser-based experience.