My complements on your great work with Ripple, it is extremely exiting by its disruptive potential.

Here is my suggestion for a solution:

You need some native anti-spam coin, which by default will have to carry some value. You also need funding to cover your investment; for coders to work on it for the future, etc. These are legitimate concerns that seems to call for some kind of a currency, to solve both problems at once.

But from this line of thought you immediately hit the big scary initial distribution problem - if you are successful: Hoarding; tulip mania; acrimony over the fairness over the give-aways. All this because what you have made easily will become not a postal stamp but the native currency for the network.  You have just set yourself up for the possibility of a particularly nasty death by success.

Solution: Freicoin with a twist, actually SpamFreiCoin.

You start off with premine of 1000 trillion antiSpamRipples. You sell them for 1 US cent (or a few sathoshis) each, or give them away for 3 years - the rest is destroyed. After these 3 years replacement of the destroyed ripples will be by demurrage, like Freicoin, about 5% every year. This is the miner grant for making new antiSpamRipples to somewhat replace those destroyed, and to have a distributed way of securing the network. Tulip mania is averted by making antiSpamRipple useless as a currency by having an extra large destruction of antiSpamRipples transferred from one Ripple account to another, above the mandatory tx fee. Like 10%: enough for you not to shrink from sending a few to your auntie and nephew, but enough to prevent any speculation on it becoming a currency.