It's fairly easy to add a charity link - to the Red Cross or anybody else you support - to every page of your site, quickly.
My personal charity of choice is the Red Cross - they help in all nations, regardless of religion, creed, color, gender, etc. Whoever you choose to support, sometimes the most important thing you can do as a webmaster is simply to lend your voice and your webspace to remind people to donate.
The program I use is
This is a FREE product.
BK ReplaceEm is an automated search-and-replace utility. You can point it at an entire directory, and tell it exactly what to look for and what to change it into. For example if you wanted to add a Red Cross link to the bottom of every page you could look for
and replace that with
<A HREF="http://www.redcross.org">Donate Now to the Red Cross Efforts</A>
BK ReplaceEm would then go through every single file in the given directory and do that swap for you. It's of course easiest if you download BK ReplaceEm onto your webserver and run the utility right on the files there. If you don't actually have access to your servers, then you will have to run the utility on your local copy of the files and then upload them. Even if you have thousands of pages, this should still only take a few hours to move them all live.
When you consider the thousands of people who are helped by the Red Cross, this is a minor issue to face in your quest to provide support and assistance to their efforts.