Partner with your local office supply store and sponsor a community computer recycling day. Send out press releases to every paper and tv station in your area. Offer to donate a computer or two, after being cleaned and fixed up, to a senior community center or other group for an even better chance at free publicity. Make this a periodic event so people think of you when their computers get outdated or need repair.

There are a lot of variations to this idea. See what will work in your area.