It's nice to see that there are many signature campaigns pops up since this january, but as time change people becomes more aware of this new campaigns to join with escrowed funds, using an escrow for this campaign makes it more nice so people will not be worried of being scam. Here's the list of trusted escrow here
https://bitcointalk.org/index.php?topic=855778.0, you can contact SFR10, lutpin or avirunes for this.
I have nothing against escrow services...thought they get all the payment process a bit more complicated...as written, I'm going to pay 50% upfront...this means that, just in case, I could be scammed and not the scammer
however, if somebody will want to use escrow, I will!
Thank you for the info!