I have just donated $100 online to the USA arm of Caritas Internationale, Catholic Charities USA.
Catholic Charities/Caritas remains probably the most low key in terms of publicity and knowledge by the general public of all the charitable social services organizations in the world. As a result, few people realize that Catholic Charities is rated the TOP provider by Charity Navigator:
11/17 - Catholic Charities USA Named Top Provider of Social Services by Charity Navigator, Ranked #2 Overall in NonProfit Times Top 100
In 2007 Catholic Charities helped over 7,700,000 people! They report on their web site that they are already in the midst of helping people who are suffering in the mortgage crisis.
Do visit their site, find out more about what the quiet Catholics are really up to in following the steps of Jesus and ministering to the poor and those in need, and consider following my example and giving them or the international branches of Caritas a donation (I wrote about Caritas about a week ago regarding the crisis in Zimbabwe).
There is an easy to use online donation page.
Also, if you are interested, you can learn what the Catholic Social doctrine and tradition is, as defined by the USCCB (United States Conference of Catholic Bishops). Also, there are great prayer resources and personal seasonal reflections (such as each day of Advent) by Catholic Charities members.