Desktop computers (eg. ubuntu) already uses preloading files (at least, popular shared libraries) to memory on boot. It is used to speed up booting and startup time of different bloarware like FF, OO, KDE and GNOME (with evolution bloat-mailer).
The tool is named readaheadhttp://packages.ubuntu.com/dapper/admin/readahead
There is also corresponding syscall: readahead(2)http://linux.die.net/man/2/readahead
There is also project of preloading daemon: http://linux.die.net/man/8/preload
