Wired on Friday/Danny O'Brien: What are the next killer apps - those pieces of software that no one thought of before but which, from the moment they appear, no one can do without?

I've always thought the best place to look for these future bestsellers is among the geeks themselves. After all, that's where all the past apps that caught fire came from - the email client, the browser, the instant messenger client. And, as it happens, I have a few potential candidates.

My list came about as a side-effect of a research project I've been indulging in for the past year. I was curious about how the most prolific geeks manage to deal with hundreds of daily emails, browsing thousands of websites, and wading through wave after wave of complex new technological advances, yet still have time to run personal websites and write handy software in their spare time. How did they do it? Not being particularly organised myself, I wrote and asked the most prolific geeks how they did it.

The results were in some ways a surprise. For the most part, they didn't do it with clever new software. Many of them organised their lives without project planning software or Gantt charts or even personal organisers such as the Palm.

Most used a simple text file, with a list of what needed to be done: the electronic equivalent of a pad and paper. (Sometimes it wasn't even the equivalent - at least one of my interviewees used the real thing. I do the same - although we both copy out the contents of that pad onto our computers at the end of the day).

But there were some daily niggles, annoyances that these alpha geeks crafted their own software to solve. Or else they ruefully described painful annoyances that they knew could be solved in software, and wished someone else would write the program to fix their lives.

And out of that pain, I saw many ideas recur. Looking down this wishlist, which I first compiled in February, I realised that you could see it as a map of what might be coming down the software river.

Solutions to geek's own problems that might just solve the bigger problems of the non-geeks - the great washed, as you might call them.

My theory has been somewhat supported by a rash of software releases that have appeared since then, offering to solve some of the problems these alpha geeks had pinpointed. I'm sure we'll see some of the other areas addressed too, by the end of the year.

First up, fast email search. Every geek I talked to has much of their most important knowledge buried in month-old inboxes and archives. Many had spent hours writing personal search engines for their email. Others craved a "Google for mail". Of course, that's exactly what Google now offers, in their Gmail service.

But Gmail requires that you send all your mail to Google's servers, which leaves many people uncomfortable with the privacy implications. A more local solution is software such as LookOut! - a search system for Microsoft Outlook users.

Another big complaint, so far unsolved: easy webscraping. It's one of the secret skills of the accomplished geek: they can get their PCs to do the boring bits of Web surfing for them. Programmers can write programs that can go to their bank's online banking page every day, pull down their account balance, and display it on their desktop to prevent end-of-month surprises. Or constantly scan eBay or airline websites, and mail their master only when they spot a bargain. Such webscraping (so called, because the program visits the webpage themselves, and "scrapes" away all but the most important facts) is currently a fiddly and fragile process that needs to be redone whenever a new site is scraped (or an old site has a redesign).

An easy-to-use application that would make scraping so easy anyone could do it would make many geeks' lives easier - and revolutionise the Web for the rest of us.

Third: file-sharing. It's a dirty compound word in the movie and music industry but sometimes geeks just want to share files - with their friends, or their workmates, or with the wider public. It remains frustratingly hard to do - especially when you want to keep those files relatively private. Ideally, what the world needs is a folder that you can drop files into, and a way of saying "I just want my brother and his family to see this picture of our meal together; this ad for my car is for my workmates; and everyone can download this movie of my cat".

There's a bit of a flood of file-sharing-for-the-enterprise applications in preparation at the moment, from Novell's iFolder, to Lotus Notes founder Ray Ozzie's Groove, to Irish contender CleverCactus, a forthcoming app written by the ex-founder of EUNet Ireland Paul Kenny. None comfortably fill the file-sharing niche, but they do come close. Expect a close fight.

All three of these potential apps are "killer" for geeks. But will they catch on in the rest of the world? I think they will.

As Ellen Ullman, author of Close to the Machine, says: "Programmers are the world's canaries. We spend our time alone in front of monitors; now look up at any office building... so many people sitting alone in front of monitors.

We lead machine-centred lives; now everyone's life is full of automated tellers, portable phones, pages, keyboards, mice."

You might not see the need for a way to search your email, or scrape the Web, or share your files - but if these canaries are anything to go by, you will. And when you do, suffering the headaches that only the alpha geeks suffer now, hope that the killer apps will be ready and waiting for you.