Don't let Microsoft's tardiness in bringing its Live Anywhere
initiative to market stop you from enjoying Xbox Live anywhere: if you've got an iPhone and $0.99 you can try out Nicholas Pike's iXboxLive app which "uses the Microsoft Xbox Community Developer SDK" to bring much of the functionality of your friend's list to your iPhone.
Sure, you could always load up your iPhone's browser (just like you do for Halo stats
) and hop on Xbox.com but then you'd miss out on the slick iPhone formatting. However, use the app and you'll miss out on functionality like messaging, thanks to limitations in the aforementioned SDK. Now we're not expecting the cats at Microsoft to suddenly develop an official iPhone app, but we'd settle for something on Windows Mobile ... heck, we'd settle for a Zune app!