If you participate on multiple Stack Exchange sites, you now have a global profile page! You can navigate there via the handy network profile link on your user page.
From your network profile, you can get a mile high view of all your activity across every site in our network. Yep, all of 'em!
The default page on your network profile is what I like to call your "Greatest Hits" -- that is, your highest voted questions and answers from all network sites.
If you missed the old reputation graph, you're in luck; you can get a similar graph of your reputation across all sites on the reputation tab of your network profile.
If you are logged in to stackexchange.com, there's also a private inbox tab that will let you access old messages in your global inbox that may have scrolled off. Just look for the "see all" link at the bottom of your beloved global inbox tab.
If you only participate on one site in the network, you may not need this stuff -- but why stop at one? We hope the new network profiles make it easier and more fun to participate in even more of our Stack Exchange Q&A; sites!