Considering you need 3 sources of citation for your speech I am going to guess that this is for academics. If you can't get enough credible sources then I would recommend changing topics.
Not sure if this will even help as some of them are probably not considered scholarly sources:
OCN just finished a BOINC session a few days ago:
Discover new drugs:
The less information you have the more difficult it is to present supporting information and facts to persuade the audience to participate in distributed computing. The more supporting evidence you gather and present will make it likely that people will choose to participate. Personally I find this topic more informative than actually persuasive as there's not really a side to take on in the topic. "Persuasive speeches focus on issues of controversy, where more than one point of view exists."
The problem is there's no controversy in the subject. Here I'll give you an example, guns should not be banned. How many people do you think will argue against that statement? Do you see where I'm getting at now? If we ban guns it'll prevent people from accessing it, but at the same time leave people defenseless. If we participate in distributed computing we might help find a cure some day, if we don't participate in distributed computing nothing bad happens. This is the best info I could give you, I couldn't find my speech book from college as it's hidden somewhere in the garage.