This post is older than a year. Consider some information might not be accurate anymore.
Import public key from keyserver
gpg --keyserver pgp.mit.edu --recv 655685AC
Import from smartcard
bk201@edge:~$ gpg --card-edit
gpg: detected reader `German Privacy Foundation Crypto Stick v1.2 00 00'
# more card stuff
URL of public key : x-hkp://pgp.mit.edu <1>
gpg/card> fetch
gpg: requesting key 655685AC from hkp server pgp.mit.edu
# import message
gpg/card> quit
1: if keyserver is set, public key can be fetched automatically
Check private key
To verify if the private key from the smartcard is usable use the --list-secret option.
bk201@edge:~$ gpg --list-secret
# nothing here
bk201@edge:~$ gpg --card-status
# smartcard accessed
bk201@edge:~$ gpg --list-secret
/home/bk201/.gnupg/secring.gpg
------------------------------
sec> 2048R/655685AC 2011-02-04
Card serial no. = 0005 0000088E
uid Tan-Vinh Nguyen ...
ssb> 1024R/3072C7C4 2011-02-04
ssb> 2048R/766C78D0 2011-02-04
