With iOS 5, Apple finally brought tabbed browsing to Safari, but they did even more than that: with it, they added a shortcut to reopen tabs you've accidentally closed.
Just like Ctrl+Shift+T on the desktop, this little shortcut is a godsend when you accidentally close a tab -- which happens a lot when, like me, you're all thumbs on a touchscreen. In Safari for iOS 5, just press and hold on the "new tab" plus sign on the right, and you'll see a menu of your recently closed tabs. Nifty!
I tested this in some of my alternative browsers, like 360 and Perfect, and it didn't work, so it looks like this is a Safari-only feature for now. Hopefully other browsers will add this small but helpful feature soon.
Restore closed tabs in Safari on iPad [Right Now In Tech]