I kept running into an error when I would go to background a bunch of processes in a shell script.
$ for i in 1 2 3 4;do echo ${i} & ;done -bash: syntax error near unexpected token `;'
I finally remembered, after some help from google, that both & and ; are line terminators, so I was doubling up on them. The correct syntax would be:
$ for i in 1 2 3 4;do echo ${i} & done
Hopefully by putting this on the blog, I will remember it. :)