Don't let me stand in the way of an opensource bundle promotion dealy-bopper, but all I meant was borrowing the concept that they use when you "buy" a bundle. Instead of letting a user directly download whatever free opensource widget you've made and hoping they donate, plant a big mean 'ole "are you going to buy that?" screen before the download link.
A free open bundle library would make this a lot easier, but if someone writes one, for the love of god, dogfood it! We can't have you starving in the streets while trying to make other altruistic developers money. ;)
Hmmm, making a more open Humble Bundle type shop could be a neat idea, and I see that openbundles.com is currently available.