Windows: Like its original webapp, the Inbox2 beta for Windows does a great job of combining your email, Twitter, Facebook, and other social messages into one sortable stream. It also respects your email labels and stars and adds simple task management tools.
Marking messages as unread is a quick and easy way to remind you to read a thread when you return to Gmail, but you couldn't mark specific messages within long threads as unread—until today.
You may be a diehard Gmail user, prone to declaring desktop email clients dead. That's fine. We still think you'll find Thunderbird 3 to be a better offline email solution, and a really convenient aggregator for all your inboxes.
Google's Wave tool suffers from a "just another inbox" problem. So it's great to see Wave running inside a tab in Thunderbird, right next to your email inbox, with a single JavaScript line.
When we taught you the first Google Wave search you should know (with:public), Wave automatically added public waves you read to your inbox, and an empty inbox quickly became hard to come by. Today, Wave fixes that with a handy Follow/Unfollow button.
Mozilla's Raindrop project showed us its one-inbox-to-rule-them-all mission, but a Mozilla designer now shows us how Raindrop might actually pull that off on mobile phones. The designs are impressive, combining email, Twitter, Facebook, and other conversations into one organized stream.
If you're a Netflix subscriber or BabyCenter member with a Gmail account, you might notice a few new favicon-type symbols and some enhanced mini-widgets in your inbox. It's part of a broader move toward "enhanced content" in Gmail.
The latest Gmail Labs offering does something that Greasemonkey hackers (and our own Better Gmail extension) have long found useful—hide label tags from the inbox, freeing up more screen space for subject lines and message previews—especially useful for netbooks.