A feature that Linux installers should have: restoring your backups
For reasons beyond the scope of this entry, I've recently been poking around Windows 7; specifically I've been poking around the standard Windows 7 backup tool, which is actually pretty decent as these things go. It will pretty effortlessly back your data or your entire system up to either some sort of disk or to a network share, and then it has one really nice feature: you can restore your system right from the installer. This works basically painlessly; you boot the install CD on a bare metal machine, find the right option, point it at your backup on a network share, and then in a surprisingly short time your entire system is back just as it was.
(I believe that Mac OS X has a similar feature but I haven't experimented with it.)
Having experienced this with Windows, I can't help but think that Linux installers should be able to do this too. It's not technically challenging and it would be a significant help for users who wind up needing to do this sort of thing; if they had a properly prepared backup, restoring their machine after a disk failure or having to replace a laptop would be pretty much a snap.
(With the right setup, making a backup would be sufficiently easy that you might get people to actually do it. It's my guess that easy install time restores would help encourage backups since they make backups more clearly useful.)
Apart from the small matter of programming in the installer, the real issues with this idea are unfortunately political. It's completely infeasible for a Linux installer to support all of the many, many options that you have on Linux for backing up your system, so supporting install time restores would mean picking one single backup system to be the officially endorsed one (along with a handful of ways to configure and use it). Linux distributions generally hate to make choices like this unless they absolutely have to, partly because doing so generally starts huge debates and rows.
(On the other hand it's possible that I'm out of touch and some Linux distributions actually already support this. If so, I can only applaud them; sometimes making a decision is what you need for usability and being genuinely convenient.)
PS: if you're tempted to implement this, please support network filesystems as well as things like USB disks. Individual people are more likely to back up to external USB disks, but in an organization it's really useful to be able to provide easy network backup and restore for things like people's laptops. You can probably guess why we're interested in this whole field. Sadly this probably means supporting doing this over Samba/CIFS, not just NFS.