There are other options. Innovations like Open Source Unionism can bring workers--canvassers and directors alike--under the aegis of organized labor without requiring the formality of a closed shop. They would lack the strength of formal collective bargaining power, but they would have guidance and a soft shield, and they could begin to build greater visibility and potentially leverage with the FFPIRG/GCI clients and funders. Open letters signed by staff, alumni and labor leaders can be sent to those clients and funders, like the Sierra Club, HRC, DNC, MoveOn, Pew. Youth advocacy organizations like Young People For and Center for American Progress are probably unwilling to single out a particular organization, but this is an issue that is very much within their mission; it's also problem spread widely throughout the progessive industry (quote Crashing the Gate). Perhaps it would be possible for these organizations, along with alumni and staff of PIRG/Fund, ACORN, the National Organizers Alliance and union organizers to form a broad-based coalition in support of industry-wide best practices and constructive initiatives like an activist guild.
(So maybe that will only happen in my own little fantasy land.)

So, I haven't done a search yet or anything, but doesn't it make sense for you to organize yourselves via FaceBook and MySpace?  That's where the new canvassing pool hangs out, and that's your best chance to create connections between and solidarity among the geographically disparate, and extremely transitory crowd of organizers and students.