To track hours each shift has a head mechanic who opens the shop, does the money bit, and writes down who is there and for how long. We have a forum for our volunteers and one section is for shift reports, on top of reporting on the general happenings of the shift and the money brought in it lists who volunteered and for how many hours. once a month a person will plug the numbers into a google spreadsheet and highlight those who have done more than 12 in that month. these are the cooperative members of the shop and are eligible for the discount. I should mention that we offer the same discount to other local bike co-ops who don't have distributor accounts of their own. Once a month they send us a list of those who have volunteered enough at their shop, these people are then also eligible for the same discount. 
-Enzo

On Tue, Nov 27, 2012 at 9:16 AM, Mark Rehder <mark@re-cycles.ca> wrote:
s casual volunteers get a card that we stamp for each hour they give us. Their sole reward from this is equal hours of free shop time. The cumulative hours are added to our automated stats form, which will show us total volunteer hours for a given month / year / etc.

Currently only our volunteer staff (those that commit to running the shop) get parts ordering privileges (cost plus tax). We don't sell new parts to the public, aside from cables and housing, so we only order new parts to help complete our donated bikes, and staff can add on to that order.