I think the true test of whether software is worth me writing about it is when it reaches the point of ubiquity. For me, that happens in the Mac world when I find myself sub-consciously keying the strokes I’d use on a Mac here at my office PC.

Need an example? Let me provide it: Mail Act-On. I subscribe to the Getting Things Done modus operandi of dealing with email: either respond/act on it right away, or do one of three things:

• File it in an @Actions folder so you can process the action later.
• File it in an @Archives folder for later reference.
• File it in an @Responses folder so you can respond at your leisure.

Now, I don’t do this on all platforms and in all situations; here at the office, I pretty well have to file by project—partly beacuse I work so many projects at once, and partly because I stink at working the ability to edit Outlook subject lines into my daily workflow. But with my personal email, save for very few exceptions, I have stuff in those three folders.

Because I use those folders almost exclusively, it was a natural for me to start using Mail Act-On by setting up filtering rules for those three folders. Unfortunately, it was hard to do, because … what keystrokes do you use? The first letter is out, as you have Actions and Archives. The second letter is out, because you’d have Archives, and wouldn’t that make you think of Responses? Yeah, me, too.

I finally adopted the following:

• `c pushes me into @Actions.
• `v pushes me into @Archives.
• `r pushes me into @Responses.

I tried to come up with the letter that was “most representative” of the word. I finally got the system when I realized that c, r, and v were near on the keyboard. It works for me; you might use some other mnemonic, and I’m not going to fault you for it.

That said, I’ve come to use Mail Act-on for this seemingly trivial task so much that I now grouse that I have no analog here in the PC/Thunderbird world of my office touching of my personal email. It’s almost as hard on me as it is to transition between Alt and Ctrl keying of things in browsers. I have to do mental shifting every time, and it’s as jarring as going from driving a manual transmission to an automatic. [I'll make do, though.]

In any regard, if you use Mail.app, are good about filing your email, and are looking for keyboard shortcuts, I consider Mail Act-On to be essential.