Two UNIX tips

Picked up two UNIX tips at http://www.ffmpeg.org/faq.html#SEC27, which I'd like to remember:

• {tail,head} commands take a {+,-} modifier on their -n and -c options, which causes the command to skip the {leading,trailing} N lines or bytes of the input.
• A bash "compound command" that is defined using flanking "{" and "}" characters can be used to apply the backgrounding operator to a list of commands