How to clone a Hard Drive to a slightly smaller Hard Drive?

Symantec Ghost v11 will do that, you can clone the source drive to any destination as long as the used data do not exceed the disk space available on the target drive.

EASEUS ToDo Backup is a free alternative to clone disks, with similar capabilities.

I've been saying it a lot recently! I recommend Gparted, I do not think you can do a copy to a disk of a different size disk straight away, but you can shrink then copy and stretch it again.

There are many other tools that can do this, but Gparted is free and easy to use.

You could shrink the partition using gparted to a few GB below your destination drive, create a partition the EXACT same size on the new drive, and then ghost the partition over to the new drive (dd if=/dev/sda1 of=/dev/sdb1 - note sda1 not just sda)