My motivation? Ultimately, I feel it's my duty as a relatively well-off human to help others (including animals) less well-off than I. Also, it's a way to promote lifestyles and causes I support (e.g. local farmers, alternative transportation, separation of church and state). But I must admit a small part is that I want to correct misguided perceptions of atheists as bad people, and to bolster charitable giving by atheists, which actually is significantly lower than other (religious) groups.
Oh come on, right? No one discriminates against atheists anymore. To the contrary. Hemant at friendlyatheist.com (which I enjoy and recommend reading) pointed me to an article written to explain/explore why atheists were not invited to the Democratic National Committee's Interfaith Gathering:
And these are the liberals of the country. :PDemocrats will nominate a Christian gentleman who respects others. It’s likely they didn’t invite atheists to their faith service because they didn’t want embarrassing guests. Atheists might bring pseudointellectual proselytizers, who are intolerant, self-aggrandizing and rude. Atheists should fund universities and hospitals. They should feed and clothe starving kids. They should act more like Christians and Jews. If they do some of that — if they contribute to a diverse humanity — they might get better party invites.I know you’ve heard this before… but you replace "atheist" with "Muslim" in that paragraph and lots of people would be out of a job. As it stands, there’s not much reaction from anyone.
Should you like to participate, here's a good list of secular/ humanist/ atheist charities for starters. I started with a local food shelter and the Secular Student Alliance; I think August will go to animals. I may start following Hemant's recommendation to join groups, giving them a donation that way. Global Giving Green also looks like a neat way to find environmental projects needing donations.
[Actually, I just want the tax write-off :P]