I work for a non-profit as an IT manager (35 paid employees, ~50 unpaid employees) for an organization that tries to reduce poverty in the world. I've worked as an IT manager at "for-profits" for a while now, and this job is by far the most challenging.
This isn't true for all non-profits, but here there is nearly no budget. Our pay-scale is fixed, and we use interns in a big way. We rely heavily on 'sponsorship' from organizations who support our cause for nearly everything we do.
Of course I take advantage of blanket donation programs (from Microsoft and Cisco, for example) and "non-profit discounts", but that's not what I really want. I don't want to pick SharePoint because it's free for us, I want to pick it because it is a good solution and fits our needs. Sadly (and by-design, surely) that price point affects my proposals to management, and I have to say "Microsoft gives it to us for free, 37signals offers no discounts". :(
But these blanket discounts aren't what I push for with vendors. I want to build a special relationship with our sponsors. I want you to donate your software or services to us because you believe in our cause, just as I believe in our cause and have taken a serious pay cut to support it. I want that relationship to be sustainable: I don't want you to feel that the burden of supporting us is greater than the reward.
And there can be a lot of rewards. We have an extensive for-profit network, and we work very close with them. We have a ton of young, highly-educated staff who come through our organization. We have a very large base of supporters who engage us, and who we engage, online (twitter, facebook, etc). The list goes on and on, it only requires a bit of creative thinking to replace dollar signs.
So I'd re-phrase the question: What are you doing to leverage a group of people who need and are passionate about using your product for an important cause which you support, but don't have the resources to pay full price?