Call me crazy, but I love email. I tend to gravitate to services that integrate with it. For example, like Jesse Stay, I often use Gmail to interact with Friendfeed. For the same reason, I am back with Backpack since I can shuttle to-do's back and forth via email. Evernote too works great with email for notes and other data. But this just scratches the surface - email is also a massive social network that's just waiting to be unleashed through APIs. Here's a taste.
A little app called Twitter Gadget is showing us the future of web services by mashing up your Twitter and Gmail contact social graphs. Once you add it to Gmail (instructions are on their site) it plops a nice Twitter client right inside Gmail. But there's much more. It also lets you selectively share tweets with any individual who is in your Friends group in Google Contacts. Your friends need to have the app installed in Gmail as well. If they do, they will see shared tweets inside Twitter Gadget the next time they fire it up. It's kinda like Google Reader shared items for Twitter.
This is a very clever way to combine two social graphs in a way that provides a real benefit to users. As our social connections become scattered among different services, I hope that we'll see more tools like these in the months head.