Most people I come across use tail -f fileName to watch files. The drawback, however, is that for a closer inspection of something I had just seen, I have to abort this and change to some file viewer (where I first need to find again what I want to check). So why not use a single program that can do both things? less fileName does this for you. What many seem to be unaware of, is that less has a built-in tail mode that can be activated with Shift-F and left with Control-C. Once back in normal view mode again, it is very easy to scroll up a few lines and inspect the interesting part of the file. And once finished, you can just press Shift-F again and are back to tail mode.