For various reasons, I've become accustomed over the years to having my desktop running 24/7, to the point that I basically depend on it. This is less than ideal, though. It's a huge hassle when I'm moving or traveling, and it's a single point of failure when something goes wrong. It also wastes electricity, and since I've spent the last year paying my own electricity bills, this is suddenly very important to me.
Therefore, one of my projects for this summer is turning it off for a while. What follows is a list of things which will be problematic.
Instant messaging: Being signed on to AIM and similar services all the time is really convenient, even if I'm not around 24/7 to actually read the messages. With a desktop, this is easy - I can just leave my client of choice on and that's the end of it. Without one, my preferred solution would be something similar to meebo, but with a persistent connection on their end so that you could stay "online" all the time, and check received messages whenever you're on the site. The next best thing would be an "AIM proxy", which does the same thing but on hardware that I control. (Unfortunately, I would have to write this one myself, since nothing like this exists yet.)
Google Talk already supports this, as far as I can tell - too bad none of the people I talk to on AIM use it. XD
File access: Right now, I have access to all my files on my desktop, which is good. I also have a remote backup service that I sync to every week or so, which is better since it gives me read-only access to files even when my desktop is off.
Read-only is less than perfect, though, so I've been looking into distributed network filesystems. My requirements are that it must work on Windows, Mac, and Linux, have some kind of security, and allow for offline editing of files. NFS is the most widely used thing, but it fails two of those - no offline editing, and nonexistent authentication. AFS seems much more promising, but I haven't yet had a chance to play with it. Unfortunately, those two are the only options for distributed cross-platform filesystems. :(
RSS Reader: I used to use Liferea, which was a pain - really slow, no remote access, etc. I've since switched to my own RSS reader, feedme, which is fast enough, and can be accessed remotely through screen. I could shift this to a server at any point with a minimum of fuss, and keep getting updates uninterrupted.
This still has a single point of failure, though; ideally, I'd like to have multiple servers with synchronized state and automatic failover, possibly only grabbing the feeds to which it has the lowest latency... hrmm. I think I'm overengineering the hell out of this one, my current setup plus frequent backups is probably good enough.
IRC: The challenges for IRC access are similar to instant messaging, but the solution is quite a bit easier. If I can get a command-line IRC client configured such that it isn't a pain to use on a day-to-day basis, then I can just run that on a server and be done with it.
Bookmarks: I know there are services that sync your bookmarks across multiple computers, but I'd need one with support for multiple browsers (at a minimum, Firefox, Safari, and Chrome). Alternately, having a webpage somewhere with a list of my bookmarks would really be just as good. Something like this probably exists; further research is required.