A page with information about the 300D firmware hack and what it can do, as well as many other tips related to the 300D. What actually surprised me a bit about it is the following small box that was on the page:
FACTOID: Did you know your 10D and 300D run DOS? That's right. Embedded in the camera is DataLight's ROM-DOS. In fact, if you use the right tool such as s10sh you can see that inside the camera is an A: and B: drive. On the A: drive reside command.com and autoexec.bat, and most interestingly, camera.exe. DOS? DOS?? Wow. Somehow a bit scary.