I hate to spoil your joy over this, but this Bristol currency isn't really a currency. As far as I know, it's fixed to the british pound in 1:1, thus it is merely GBP in another form. The reason why they started this project is that once you exchange your money to the Bristol thing you usually spend it there. If you just had GBP you would likely spend it somewhere else. So it helps the local economy. From our point of view this turistic attraction is irrelevant.
Feel free to correct me if I'm wrong. I got my information from newspapers and it may be wrong.
Agreed - most local currencies are closer to the Gift Card model used by shops in that it limits where you can spend your cash (except you can convert it back to other currencies, at a push). From the spender's perspective, that's a big limitation - "Like Cash! Only less useful!" - you need to offer a *lot* of discounts (like, system-wide) to make it meaningful/attractive to spenders, and local businesses often don't have the margin to do that.
I'd like to see more development around reasons for local currencies - but realistically I think that has to come from, or feed directly into, local taxes/government. Could local taxes be tied into transactions in the local currency for example, e.g. spend Brixton Pounds to give x% to a local development fund? Given that the main draw is to keep money "local" rather than disappear into international companies and pensions, doesn't that open up scope for more local feedback?
I'd like to see more online presences for local areas too - electronic local currencies could feed into this nicely, like a kind of gift card for an aggregated online store for an area. An "eBrixton" site could bring together items from shops in Brixton, which you could then buy online using Brixton pounds, or pre-order online and pick-up in person. There's opportunity for gifts if you know someone's going to be visiting a place, but also means that if people have a Brixton Pound leftover after visiting for the day, it's not just lying around in a drawer being forgotten about.