What's with the limited number of available organizations to mine Bitcoins for?

We've chosen to only add organizations that have their own BTC hash to accept donations at, so that we can maintain total transparency about the operations here at Bitcoins for Charity. It also allows us to offer donors and miners granular metrics for each entity.

What's the difference between donating Bitcoins and donating USD/EUR to a charity or NPO?

Bitcoin is a cryptographic currency, and anonymous by nature. What this means is that all donations are also anonymous in nature, unless a donor chooses to identify themselves. Bitcoin's underlying peer to peer architecture allows organizations to be completely transparent about donations received, without having to provide their own platform for metrics; they can focus on helping those they set out to.

I don't have an OpenCL/WebCL enabled device that works with KRAD, how can I still help?

Don't worry, you might not be able to accumulate Bitcoins as fast as the miners with Radeons, but you can still acquire Bitcoins to donate: