How big do we want to get?
As big, or small, as our supporters want us to get?
What happens when we run out of charities, when every respectable organization has either accepted our BTC or said "No thanks"? Does the Bitcoin100 story end or do we start a new chapter?
We will likely never run out of charities. There are new ones popping up all the time. We may run out of money way before then though. When bitcoin is ubiquitous, and everyone uses it anyway, then we will end.
I agree with Peter that the funds donated so far should be considered earmarked for charities only. Rassah, Phinnaeus and I are covering the minimal overhead expenses for Bitcoin100 out of our personal funds but if we begin accruing additional expenses it might be wise to keep everything as transparent as possible.
We could set up a separate BTC account, I guess... Though I'm not sure how it would work exactly. It's not like we have revenues, and 100% of our income budget is for charities. Maybe we could post updates on things we need (like add spots and such) and have people donate to fund those specifically? Though that would require people to either donate twice, or choose between donating to our operating and our charity account. Another idea is to set up a % of future donations from a specific point to be spent on operating budget. I.e., all donations so far are charity only, and all donations starting on some day in the future will be split with 5% going to operating. We can then adjust the % as we need more or less.
If we start spending other people's money on anything other than donations, it might be best to register and start acting like a "legitimate" non-profit.
How come?
It might be interesting to see how bitcoins and the blockchain may be used to allow our books to remain open to review by anyone and everyone. I for one would like to make a real effort to keep funds in a closed "bitcoin only" loop.
Of course. BTC100 money goes into the BTC100 address, and any time I spend anything from it, the change goes right back to the BTC100 address. That way, all money is kept in one place, and all transactions are trackable from one address. If we set up an operating account, I would set it up the exact same way, with 5% (e.g.) transfers coming in from the main BTC100 address, all change on expenses going right back to the operating account, and all expenses noted in the blockchain.info address transaction list.