UPDATE: Bummer! The CEO of the company behind the software (apparently, a one-man-band) has been hired by Twitter, but they don’t intend to keep the service online. :-(

SOLUTION: 3mindme is a minimalistic and efficient replacement created and mantained by David Barrett. You can send/forward email to @3mindme.com (e.g., 3days@3mindme.com) and it will bounce back at the specified time. No calendar and other Sandy frills, but it fills the gap of a “snooze” button at your inbox</del>.

NEW SOLUTION: 3mindme also went belly up, so I’m currently using NudgeMail. It’the same thing: you send/forward e-mail to things like saturday@nudgemail.com or tomorrow5pm@nudgemail.com and it comes back to you. They are on a free beta right now and promise to continue having a free version once they get out of beta phase.

My email inbox is the most valued piece of “virtual real estate” in my life – and I am not alone in using the “act on it or archive it” approach to email. Every email that remains in my inbox is a survivor – a call-to-action item, in the best GTD style. And it works: a near-empty inbox makes me more focused, productive and relaxed.

There is, however, a small crack in this routine: some emails do not require immediate action, but cannot be archived and forgotten either, and they keep lurking in my inbox, stealing bits of my attention every time I go there to check for new stuff or find higher-priority things to do.

Enter I Want Sandy, a web application that combines email and calendar in a very smart way. It allows me to literally time-shift email: I just forward it to her, with a subject such as “Remind me to read this tomorrow in the afternoon”, and the email comes back at the specified time (I can be as specific as I want – she is quite good at guessing the details when I get vague).

This way I can keep in my inbox just the items to which I need to pay attention on the spot. Everything else vanishes and returns only when it is the proper time for it to be handled. And soon I started to using her to remind me of less-important things (after all, it’s just sending an email) – also uncluttering my iCal/Google Calendar.

After having been captured as a user, I started wondering – as a developer – what makes this application so interesting. Of course it uses technology in a very smart way, provides lots of features besides the ones mentioned here and has interesting origins, but I strongly believe it stands out from the crowd due to three usability factors:

a) Besides supporting sophisticated ways of interaction (such as Twitter and SMS), its core is pretty much the combination of two very tried-and-true technologies (email and calendar), but in a very novel approach: by using email as an interface to calendar;

b) It presents itself in a way compatible to its paradigm shift. I know that it is an application and not a person – but the metaphor works so well that not only do I really feel as if I’m asking someone to help me rembember my stuff: I also refer to it as a person (as you have seen multiple times in this text – it’s unavoidable after you begin exchanging more emails with her than with anyone else);

c) It simply works. For every request that a cleverly constructed algorithm can reasonable be expected to undertand, it does what I expect it to do. Comparing it to clumsy, more-misses-than-hits systems (such as the ones on Google Calendar and Outlook) reminds me of the quantum leap of going from Yahoo/AltaVista to Google.

(One might argue that “c” is a technology issue – but I see it more as focusing the technology efforts on the right place than anything else.)

Will it be a hit? Nobody knows. But it is a rare case of a real novel approach to an existing, “solved” problem. I would have been proud of creating it – and still hope to be able one day to help creating something as ingenious as this.