One of the first gun bloggers to take me up on this challenge was The Packetman. I've never had the pleasure of meeting him in person, but we share common sensibilities. We're both shooters, Second Amendment advocates, and libertarian curmudgeons.
This is also a personal cause for him, because his Dad fought prostate cancer and beat it. You can support his fundraising efforts for the Prostate Cancer Foundation here. Drop by his blog and tell him you support what he's doing, and drop a few bucks in the hat for cancer research while you're there. If even 20 people who read this donate only $5 each, that's $100 toward a very worthy cause. Every little bit helps.