I've just launched a campaign to get the IEC Power Symbol into Unicode!
A couple of months ago, I asked this question on HackerNews
I was looking for the electrical "standby" symbol - AKA IEC5009 / IEEE1621. You know, the circle with the line through it. The one that's on every single bloody piece of electronic equipment produced since the mid-1970s.
It's not in the Unicode standard.
What other useful and/or important symbols are missing from Unicode?
The proposal will be considered in early February - and I'll let you all know the outcome.
In the meantime, we've created a Web Font which you can use if you want to display the symbols.