The ethkey guide mentions how a regular address can be obtained from an ICAP address. But it doesn't mention how an ICAP address can be obtained from a regular address.
Occasionally, however, it's important to convert between the two. ethkey provides the inspect command for this purpose. When passed any address, file or UUID, it will tell you information about it including both formats of address.
Since most people already have regular hex addresses, can they be converted to ICAP without having to create new private keys? Or is there a way to use ICAP without needing to create a new ICAP address and sweeping the funds to this new address?