How to check your ISO file for consistency before buring it to disc or using it

When you download a large file from the Internet there are chances that the file might be corrupted during download. In order to be sure that the download is not corrupt, you can always check its md5sum.
In case of Ubuntu you can check the md5 sum of the downloaded ISO using

md5sum ubuntu-11.10-desktop-i386.iso

Then you can compare this with the md5sum available on the website, from where you downloaded the ISO.