Note, I am a believer in giving, just not in soliciting people in the middle of nowhere and putting them on the spot. It is tacky. That said, here are ways I have tried to avoid these unfortunate solicitors:

• "I don't have a credit card. I don't believe in them."
• "I don't remember my bank account number."
• "I have no money on me." (On my way into the movie theater to buy a ticket).
• "Um...you guys have a website, right? Yeah, yeah, I'll look into it."
• "I just donated to the last guy."
• "Um, I'm in a hurry." (My leisurely slow pace suddenly quickens).
• "I....um...." (mumbles something incoherent and saunters away)