EllipticCurveCrypto
ECC-DSA RFC
Application Support
OpenSSH? : In version 5.9p1 at least (Ubuntu Precise)
GnuPG? : In mainline, not in any distro builds I have.
OpenSSH
Parameters
Recommended key size : 521 bits
Create Key
ssh-keygen -t ecdsa -b 521 -C "some name for my key"
GnuPG
No support yet.