algo=[algo-name]; rm foo.*; time gpg --cipher-algo $algo -o foo.$algo -r [precipient] -e 100mb.bin

Encryption to a 2048 bit Public Key
Blowfish = 19.89 seconds
AES = 17.93
AES-192 = 17.20
AES-256 = 17.93
Twofish = 16.33
3DES = 32.58
Cast5 = 17.20

Encryption to a 4096 bit Public Key
Blowfish = 20.01 seconds
AES = 16.71
AES-192 = 17.45
AES-256 = 18.05
Twofish = 16.39
3DES = 32.51
Cast5 = 17.24