When we're trying to get a handle on our finances, giving money away doesn't even seem like a viable option. However, for most organizations, a small donation makes a difference. UC Berkeley and Craigslist joined forces to create a research-based website, called Donation Dashboard, that helps you choose charities in line with both your interests and your budget.
The underlying purpose of the site is to improve non-profit donations, and I think it's a useful tool for those who haven't been donating because they think it's beyond their budgets. The site is very easy to use and you don't have to provide any personal information, not even an email address.
First, you're taken through 15 non-profits that you rank on a scale from 'Not interested' to 'Very Interested', and a filtering algorithm is used to generate a statistical model of your preferences. You're then presented with a chart of their recommendations and asked to enter an amount that you wish to donate. Finally, the site divides your top charities by the amount you entered.