While everyone (interested in this topic) is looking at internet applications, using and abusing of buzzwords like "Web 2.0", "mashup" or "Ajax", I think the next wave of cool software applications will be related to personal, local storage and organisation of documents.
Of course, you have > 2Gb of storage in most free e-mail services. Of course, you have broadband access at home, at work and nearly everywhere you go. Of course, you can watch movies on the web. Of course, you can share photos on the web. Of course, you can download songs and books on the web. Etc.
But you need personal, local storage to keep all this data (photos, videos, music, even MS-Office documents are becoming bigger and bigger). Some companies (like BeInSync, FilesAnywhere or Nomadisk (*)) are trying to sell you "hyper-cool" (emphasis is not mine) remote storage solutions. These solutions are good for a small amount of data or for personal usage, not for companies with IP concerns or companies/individuals with privacy concerns (data not encrypted during transfer or left in the host computer hard disk / cache, e.g.).
In this respect, Bill Burnham wrote a somehow interesting blog entry, the storage explosion (based on a Tom’s hardware article). After bringing to mind the "scarcity and abundance" theory of IT development, he noticed the computer storage capacity increased 5907 times in 15 years (more than CPU perfs or network bandwith, if such a comparison can be done) while storage costs dropped by more that 99%! After a short review of current and (near) future hard/flash disks specifications, the obvious question is: "What Happens In A World Awash With Storage?". The forecast is obviously "very interesting implications for both software and internet related businesses".
Some applications are already taking advantage of this storage-flooding … Look, for example, at all the GNU/Linux OS + applications you can use from a simple Flash disk: Knoppix, Flash Linux, Slax, Ubuntu, … It even works with embedded systems and Windows! Other applications are ready to crawl and let you search your hard disks for documents: Beagle, Google Desktop, Spotlight, … Some companies are starting selling kind of virtualization packages based on the increasing amount of space on a USB drive : see MojoPac, for an example on Windows or simply portable apps (without OS). Etc. Where your imagination will stop you?
Since it costs nothing, doesn’t hurt and a lot of people did it before me, here is my prediction for 2007 (in the IT world): the advent of personal storage solutions. What’s yours?
* btw. Nomadisk is just packaging free software in a proprietary package. They provide some sources upon request but I wonder if they comply with the other open source licenses since they don’t provide the modified source code. Or their application is so trivial that any software engineer can write the same software, without even modifying the original components?
P.S.: Ok, now, let’s concentrate on my Ph.D. dissertation …
Jean-Etienne's blog 
Nomadisk indeed uses Unison, Plink, Crosscrypt, all open source tools. But it goes much further than! On top of that, Nomadisk 2.0 will make these tools superfluous. Of course we comply with all relevant licenses in the meantime.
The word hyper-cool is not ours either. We are cost-effective, functional, but most of all very user-friendly and SECURE. In case you’d be looking for a string of adjectives to relate Nomadisk to… Hence our explicit intention to target the professional market. Not only are data protected locally with passwords and encryption but also traffic to the server is encrypted. And storage space is limitless.
We do not know where you have information from but I happily challenge you to give Nomadisk a serious try. It’s free for 30 days. Just have a look on http://www.nomadisk.com.
By the way, do continue. A good, solid blog. It is always nice to hear a critical voice.