If you ever delete your IOS image and the system reboots before you get the new one on or if you upload the image and it is corrupt you will need to know how to upload an image from ROMMON mode.
Here are a sample of the commands, replace the entries with your specifics:
rommon 1 > IP_ADDRESS=192.168.1.5
rommon 2 > IP_SUBNET_MASK=255.255.255.0
rommon 3 > DEFAULT_GATEWAY=192.168.1.1
rommon 4 > TFTP_SERVER=192.168.1.10
rommon 5 > TFTP_FILE=c2600-adventerprisek9-mz.124-5a.bin
rommon 6 > tftpdnld (this command kicks off the tftp download)