Have you ever wanted to wait with performing a task, such as downloading a file, in order to save system resources? You should check out the "At" command since it's exactly what you need!
Yesterday I wanted to download a medium sized RAR archive from a friends FTP. His connection isn't good (as a matter of fact it is the worst ADSL I've ever seen...), meaning I couldn't download it while he was using it. Solution: set the download to start at 2AM.
First I created a plain text file containing the instructions (wget with an URI containing user and pass for the ftp) named "todo". Then "At -f todo 02:00" scheduled it.
At will assume 2AM to be 2AM the next day if it has already occurred. Run Atd to see your queue.
I'm glad I took the time to read the manual and learn to use this piece of software, it certainly will make my life easier. Set to remove shared files from my web server before I forget it, convert a video while I'm on lunch or perhaps schedule a reboot - awesome stuff!
In short: At is awesome!