To be fair: downloading a .iso file, burning the image onto a blank disk, rebooting and entering bios setup, setting boot device order , inserting disk and rebooting again, partitioning disks and doing install process isn't something that an unsophisticated user is going to be able to do without significant guidance though.
The BIOS flashing does add an extra risk factor though, prepare for many "Linux fucked my PC!" rants from users who screwed up the flashing process.
I've used UNetbootin, and as far as I know, there is no way to do a netboot/install without any media.
I took a look at the site, and it doesn't appear to have any information about that. Are you aware of some functionality that isn't listed on the site?
For what it's worth, UNetbootin is a really nice way to create liveUSB drives that you can use to install Linux/BSD.
I think we have different notions of what "network install" means. Yes, you can download packages from the web during the install (perhaps booting from a minimal install, as most net work installs do).
I was really more interested in netboot installs, where the machine downloads a boot image (via TFTP generally) and does the install from there.
In fact, no hard drive is needed in the machine if you want to just boot an image from a network share.
Apple uses a technology like this to reimage boot drives:
The BIOS flashing does add an extra risk factor though, prepare for many "Linux fucked my PC!" rants from users who screwed up the flashing process.