Apparently today they're nominating it to be a day where you go out of your way to do something nice for someone else. I guess they're wanting to make September 11th a national day of charity, good deeds and volunteer service.
I do volunteer work all throughout the month a various places and am thinking about adding a couple more organizations to my list including our local animal shelter.
You don't like *have* to go out and do something, something simple as asking someone you don't normally talk to how they are, or saying hi to that really awkward nerdy kid no one likes at school or asking an eldery woman if she needs help with anything.
Or, if you'd rather just sit back and not have to phsyically do anything, donate a small amount of money to a charity via the internet or a local one. Or, clothes are something that are very needed. If you have a good will, salvation army, etc and a women's shelter or men's shelter is a very good place to donate clothes and I would highly suggest talking to them about donations first.
http://mygooddeed.org/