Most of my continuity testing is simple - all I want to know is if there is continuity, and the actual resistance is immaterial. I picked up a piezo buzzer at a hamfest several years ago with the intention of building a tester, but forgot about it until I found a nice little case at a swapmeet for $.25. The case even has a battery compartment which makes it really handy. The tester is easy to build - just mount the buzzer, install binding posts and connect the battery. Note that the binding posts are three way - they will take a banana plug, you can twist a wire around the posts and secure them with the nut, or you can insert a wire into the holes on the posts. This makes it handy for checking continuity on circuits where you have to string a long wire to reach everything. Click the thumbnails to see larger photos.