Tonight, I found myself having to copy the AnyConnect binaries from one ASA 5505 to another without a device on-LAN to TFTP to. I did, however, have a public FTP server that could use to move the data around.
This feature seems to be relatively un-discussed, so here is the syntax.
ASA/Router Binary: my-win-package-k9.pkg
FTP Server: ftp.myserver.com
FTP Server User Name: aarong
FTP Server Password: password1
copy disk0:my-win-package-k9.pkg ftp://aarong:firstname.lastname@example.org/my-win-package-k9.pkg
Yes, it's really that simple. Would have been nice if someone told me.