There are various VMware products suitable for running our images. VMware has decided, probably because of the competition from VirtualBox, that at least one of these should be available for free and that is the VMware Player.
At first you should download one of these:
2. VMware Workstation
As indicated above, there is another product, called VMware Workstation, which is also meant for desktop use. The Player is the light version, while the Workstation is more for professional endeavors. Accordingly the former is free while the latter is not.
Depending on your needs the Player will in many cases just do fine. If it turns out that some feature you need is missing, there is always the chance to buy the bigger sister.
Here is a screenshot of the Debian Squeeze appliance as the guest system running in VMware Player on a Windows host system.