I've always wondered though, is it as easy as copying the disk image on my current physical server and uploading it to Amazon? I would need the same configurations and packages in place and I'm just trying to understand if I would have to remember every configuration I ever made to get me to this point, or if it's as easy as a simple copy & paste
You will need to start with an EC2 image (AMI) of which there are many both from Amazon and 3rd parties. Some of those AMI's may have close to all you need. I personally started with a bitmami image (http://bitnami.org/stacks). Once you have all your configuration done on that you can create your own personal AMI from it and use it to create additional instances (dev, staging, different customers, etc). That AMI will work for creating different instance sizes (memory/CPU). But I don't think there is a way to export an AMI and use it outside of Amazon.