Create VM image and deploy at customer site

Complete newbie here -- my apologies if this has been answered elsewhere.

I have an application running on Linux on a physical server.  We have an ESX4 server in our environment running a couple of dozen vm's.  Is it possible to somehow convert that physical server to a VM image, then deploy it on an ESX server at a customer site?   Can someone point me to documentation outlining how that could be done?

THANKS for any help you can offer....