I don't know what are the insides of a digital eye piece of a telescopes but I think I succeeded in faking one for a pretty cheap price. For long I wanted to capture what ever I see through my 'Beginners Astro-terrestrial refractive' telescope. A month ago I decided to buy some gadget that will do this for me. Found a digital eye piece that would cost me 98$ along with taxes. Oops!! my telescope didn't cost me so much (Rs 3500 or 68$) and I decided not to go for it. There were some youtube videos that suggested replacing the telescope's eyepiece with a webcam. That didn't work until I figured out that 'Optic Physics' will not let me use a simple webcam instead of the eyepiece. I tried attaching the eyepiece with the USB webcam. It worked but the webcam was a VGA and images were poor. Then finally it struck me, "why don't I use my old cell phone with a 2 Mega pixel camera??!!". I fixed the eyepiece to align with the camera's focal length and now I was able to clearly capture what ever I saw through my scope. I was looking for a wired connection to my laptop but I ended up in a better wireless option. I have definitely saved so many dollars.
Check out the below images
Few easy steps:
Fixed eyepiece over the cell phone camera using insulation tape (used a 50X eyepiece)
Camera axis should align with the 
eye piece axis
eye piece axis
Telescope fitted with the digital eyepiece
