As you know , trading with bitcoins (actually buying something ) is an issue.
Most users are "sitting" on their coins , waiting for the value to go up and down.
I don't think many people are actually buying stuff with it.
An idea that might make a change is "negative interest". If you don't use your coins for for let's say a few weeks , you pay a "tax" for not using your coins and the system automatically reduces a certain amount of coins from your account.
The reduced value goes back to the "system" and now new people can mine them as a new coin.
Pros :
1) People will trade their bitcoins and stop accumulating them !
2) The trade volumes will get huge
3) High trading volumes will encourage more and more people to use bitcoins so the amount of bitcoin users will get dramatically higher.
Cons:
1) People can move money from wallet to wallet so their "old" coins won't pay tax. Need to think about technological solution for that
2) People don't like paying taxes ....
Thoughts ?
Never work because there are any number of ways to "sell things" or trade with yourself directly or via a friend. Its just too simple to do to even contemplating ways of stopping it. And besides, taking bitcoins off people is akin to EU banks taking money out of customers' bank accounts. One of bitcoin central tenets is "people control their own money" to do with as they please. If that includes hoarding (i.e. saving), so be it. People have a right to save, a right to spend, a right to give away, to do what the heck what they want with their coins.
People won't sit on their coins forever. As more and more services take bitcoins (this week piratebay, porn, dating sites + many others I have missed), and the volatility decreases, people will slowly start to spend and when that happens, there is no going back.
Rome wasn't built in a day. The progress of bitcoin in 3-4 years has been staggering. The progress in the next 18 months will be many times as great.