Have you ever had to copy a fairly large file on the command line and wondered what the progress was? The command line progress bar seems to do a decent job at showing the percentage and estimated time of a copy.
Description from the site:
Bar is a simple tool to copy a stream of data and print a display for the user on stderr showing (a) the amount of data passed, (b) the throughput of the data transfer, and (c) the transfer time, or, if the total size of the data stream is known, the estimated time remaining, what percentage of the data transfer has been completed, and a progress bar.
Bar was originally written for the purpose of estimating the amount of time needed to transfer large amounts (many, many gigabytes) of data across a network. (Usually in an SSH/tar pipe.)