G1 Create Image of Current State Is it possible to create an image of my phone (G1, cupcake) so that I may revert back to it at a later date?

I'm not scared of using the Android SDK, I only needs the steps to create the file.
You can use nandroid to do this.

If you update your recovery image to Cyanogen's 1.4 recovery then it has nandroid built in.

These are tools from the community and are not officially tested or supported so make sure you fully understand what you're doing before using them.