I've been using eagle a bit, and I have found it necessary to build a number of devices. It's a bit of a struggle at first, but once it's done it's done.

Since we're on this subject, does anyone know a way of automatically filling in space on circuit boards? I make my own boards, so the less copper I etch away the better. As of now I have to put in a bunch of squares and triangles manually, and when I want to change something on the board, I have erase many of them and put them back. Now that I think of it, there may be a way to do this with photoshop or something just before printing the negative (basically draw black lines around all objects). Any thoughts?