But they can also be used as a currency similar to bitcoins, and some people are hoping to use that similarity to make money on the chance that XRP prices go up, so the speculators have inflated a huge bubble.
ok
1 - why would ripple want to associate themselves as a currency? they will be shut down in a heart beat
2- so people think that ripple will blow up enough to fulfill 100 billion ripples, and each ripples does 1000 transaction, ok
i seriously give up on this
1 - They are making the currency because they think it solves some problems in the ripple system. Their goal is to have many people running the servers so the network will not be subject to government shutdown (sort of like how bitcoin is not afraid of government shutdown).
2 - people are not speculating that the ripple network will be used for 10 quadrillion transactions, they are speculating that the ripples they get will be sellable for more money than they bought them for. The destruction of a very small quantity of ripples over a person's lifetime has less to do with their exuberance than the fact that the total supply is finite (kind of like how people say "there will only ever be 21M bitcoins, therefore bitcoins are deflationary"). What people who are speculating like this are not taking into account is that OpenCoin holds billions of ripples, and anytime they want they can release them and push down the price.
It is kind of like how everybody "knows" Satoshi is sitting on like a million bitcoins, and anytime he wants he could flood the market and drop the price. But even if Satoshi does still control all those bitcoins (if he has not lost the private keys for all of them) that is only 10% of the total currency, and once he did it the market would absorb those and just keep going. But Ripples, on the other hand, nobody knows how many have actually been given out and how many the creators are still holding. There is some amount floating around right now, and they are going for about 0.125 mB, OpenCoin could dump enough to double that float, and then double it again, and then double it again, and then double it again, each time crashing the market price of ripples. So, in my opinion, investing in ripples is extremely risky, even more risky than bitcoins.
Hope that helped.