I also think the best way would be to integrate a donation mechanism as a first step, and a store with some T-shirts/Stickers. I see Hubski as a content aggregator with a better social dimension than most websites because the community is small and we get to know and relate to each other.

As for the integration, to answer your question thenewgreen :

1) It should be on the top. I know it's more invasive this way, but I don't see a lot of people donating anything if it's at the bottom. I didn't even knew there was a bottom bar until recently and the introduction to the random link (which is great, btw).

2) It should be an easy integration with Paypal or Stripe. We should have the choice to do a monthly donation or a one time donation.

3) As for the incentives to donate, I don't think you need any. The community seems close enough to understand the goal here : maintaining a great place to share things and to talk about a lot of various subjects. But I think opening a store with some T-shirts and Stickers could add a source of revenue.

You can inspire you from these great blogs : http://www.farnamstreetblog.com/donate/ ; http://waitbutwhy.com/support-wait ; http://www.brainpickings.org/