what if we could flag certain btc with something like "this cannot be transferred from this address within X period" (able to be changed by the owner)? for example, in a long-term savings situation, this would allow even an unprotected walled, assuming all coins were marked, to be safe for a period of time.
This is an idea for those who think that Bitcoin must either take over the world, or die.
It would create the concept of Bitcoin "bonds". You could create a mechanism for individuals who are interested in seeing the exchange value of Bitcoins rise, to pay interest on the bonds. Perhaps, with a sophisticated multisig contract, it could be done in a de-centralized way. It almost doesn't even matter what the interest rate is, since there will be plenty of people who are holding Bitcoins for the long term anyways, and would be happy to lock their Bitcoins in exchange for more in the future.
The concept is that Bob pays 1 BTC, and in exchange receives a transaction that time-locks 10000 of Alice's Bitcoins, for a year. At the end of the year, Alice gets 10001 BTC back. I have no doubt there are people who would do this.
I wonder whether this is Gavin's "secret idea". It would add stability. It's sophisticated enough to be on his level. And it's fairly obvious based on recent events.