Use Firefox?

Ever close a tab by mistake?

Ever wish you could go back to the site on the tab you closed 15 minutes ago?

Then this is for you: command-shift-T (Apple OS) or control-shift-T (Windows). Not only will this reopen the last closed tab, there appear to be an unlimited levels of undo within a given cached session (at least up to a dozen or so tabs, which is as far as I’ve cared to test). This is something I use every day, and I’m always surprised how many people don’t know about it.

Convenient? Youbetcha. I know there’s a lot of people out there tricking out Firefox with <a href=”https://addons.mozilla.org/en-US/firefox/ “>add-ons</a>, but I’m one of the vast majority for whom Firefox is fine pretty much right out the box (although I do use the OPML plug-in for getting certain RSS feeds into Google Reader).

But then again, maybe this handy little shortcut is too convenient: the other day I noticed that (unless or until a server-side inactivity timeout occurs) cmd-shift-T takes you right back into your authenticated SSL sessions, too… (!) And since it will also take you to pages you’ve deleted from the browsing history, deleting just that isn’t enough (actually, the browsing history is less dangerous than the cache, because since it’s just a URL string, any SSL sessions would have to be reauthenticated).

So let this be just another warning to delete that cache on public or semi-public machines! (I can just picture someone up to no good hitting repeatedly using this shortcut on any running instance of Firefox they come across …)

And backup your local data.

And eat your vegetables.