I have used my GC list to contact registered members in my state not only for volunteer opportunities, to gain walkers but also, if they cannot attend the walk, they can pre-reg with me and get a t-shirt at the very least to commemorate the event. I have had 7 emails in return ordering at least 2 shirts per email in response from just two days ago. This is a good idea for those who want to participate from a long distance and lend support. For each that responds to the T-shirt, I may send them another email asking if they would just post the event flier in their area/work to help gain more members/walkers/doantions.
Just another idea from your Friendly Neighborhood TIME! :-)