Launch Plan

So early plans for the site are, in approximate order:

Register the domain, create the site, write the needed scripts (DONE)
Send out an appeal for a few initial volunteers who live in a different far-away areas, get them to send requests to each other to seed the Gallery with some content. During this early period, I will sending personal mails to photographers when a request is made that falls within their area.
After at least 10 assignments have been filled, do some limited promotion on misc lists, news groups and forums. Carefully avoid being obnoxious. At this point, automated mailings with a simple administrative interface should be up. Photographs can opt for a weekly digest of open requests.
If and when the site is getting more than 1,000 page views per day (or becomes intolerably slow,) move to a real colo with better outgoing bandwidth
In longer term, find other tasteful ways of sending traffic to the site, perhaps including permanent links from relevant photography sites, tools to help requesters post links to resulting photographs on blogs.