Get your BN curve here
It looks like some researchers at RWTH Aachen University have an on-line tool for creating BN curves. These are elliptic curves that are particularly useful for pairing-based cryptography, like the identity-based encryption that Voltage uses. If you're interested in implementing pairing-based cryptography, this is a very useful resource to have.
It's generally true that there's no such thing as a free lunch, and this even applies to identity-based encryption. From the user's point of view IBE is great because it's simpler to use than alternatives. From an administrator's point of view IBE iss great because it's extremely simple to keep running. These two combine to make its TCO much lower than the TCO of alternatives.
On the other hand, all of these good features don't come for free, but they really involve things that users and administrators don't see. In particular, it can be very difficult to find elliptic curves that are suitable for use in IBE algorithms. Most elliptic curves don't work very well for this and it can be a bit tricky finding ones that do. BN curves happen to be an example of a type of curve that do work well, so having a place where you can get parameters for such curves can be very useful.
The parameters that you can get from this on-line tool aren't optimized to give you very good performance, so they're not what you'd want to use in a shipping commercial product, but if you're just doing development and testing they're very useful.