I recently had a need to do up a basic schematic on the computer, and just save it. The first thing I attempted was Dia, which I've used before for basic software diagrams. It's half-decent, and when I did the software diagrams it pretty much did what I wanted it. However for schematics I find it isn't so great and I thought there might be a better alternative.
I did a quick search in Synaptic for "schematic" to see what it would come up with. There are a whole bunch, and I went through a few of them. The best one that I found in there was gEDA, for the following reasons:
1) Massive library of components. I had a specific IC for the circuit I wanted to draw, and it was in the library. I was expecting to have to create some generic IC with a certain number of pins, but they had the one I wanted. Also, the library has a search feature, so you don't have to scan through to find the one you want.
2) Wires can be drawn easily, and as you want them. They also will snap to other wires and components. If the components have certain pins (like ICs) you can easily choose which pin you want to connect to.
3) Interface isn't too unwieldy. I would have a few suggestions (maybe I can add them as a little project) but other than that it is very functional and stays out of your way.
There might be some better features you might want, but these are the ones that I like and needed for this specific case.