If you ask me, local currencies are going to have to be involved if we want bitcoin to go mainstream. People like to use cash to do day-to-day transactions and local currencies are an excellent way to accomplish that. How about if we get local currencies to be backed up by bitcoins?
If you look up examples of local currencies you can see that they are actually pretty smart in getting people to use them. Basically what they do is tell merchants to offer some sort of discount for people who pay in xyz local currency. If people want that discount then they have to use the local currency. The merchants accept the local currency because they know the consumer can only spend it at merchants who accept the local currency. So if you are a mom & pop store you want to be able to compete against wal-mart you can do that by accepting these local currencies. Likewise, if the local currency is widely used its much easier to get new businesses to accept them. Would you really want to open up a cafe and not accept the local currency when 90%+ of the town prefers to use them? That way there is an incentive for both consumers and businesses to use them. Consumers get a discount and businesses get a competitive advantage against businesses that don't accept them. Plus there is always the feel good benefit that people get when they, "support the local economy."
If you ask me bitcoin + local currency is the absolute perfect combination. Especially if you combine it with technology such as bitbills.
Also its important to mention that there are several widely used local currencies in the USA, which are: berkshares, and Ithaca hours. There are hundreds of actively used local currencies all over the world.
I say instead of reinventing the wheel lets go to these existing local currencies and tell them about how bitcoin can improve their local currency.
Here are some examples of local currency:
Ithaca hours. This note is worth about 10$ USD.
Berkshares used in berkshire region of Massachusetts.
Ukiah hours used in Ukiah, California
Disney Dollar, used at Disneyland or Walt Disney World
http://youtu.be/rYc1u8eqhiM