I run a store online and would like to offer a discount for people who pay with bitcoins. We can afford to run a 10% discount, but on a $40 product that's not going to be compelling enough to get someone to figure bitcoins out. I want to apply for a grant, or something, that will help me give 50% discounts.
Such a fund could encourage producers to accept bitcoin AND encourage consumers to use bitcoin.
If I had a billion USD, I'd spend $200k on BTC for myself, $1M on BTC for this fund, and $100M on advertising, apps for phones and stores, and startup capital for BTC-based companies. If you have a billion USD... please get cracking!
Even if you just have 100 kBTC, you might consider spending 1 or 2 of them on a fund to help businesses encourage BTC use.