My favourite tool for 2009 and 2010 — while I was mostly offline — is Google Reader, the feed reader offered by Google for "popular browsers" (read: IE6, FF2, or better), because it dutifully kept all my subscriptions, and still works like a charme.
In a Gmail blog article Google reported a bug in the Gmail service, apparently my account belongs to the 99.98% not affected by this issue. The article mentions an Apps Status Dashboard showing the published issues for various Google services including Gmail. Some years ago I would have added this page to my bookmarks, and checked it when something went wrong. Today it is much simpler to subscribe to the relevant RSS feed — hopefully this results in no updates when there are no known issues.