I've not seen this piece of software mentioned by anyone else on the forum, so i think it's still relatively unknown.
however, it's an extremely useful tool for previewing all of an avi which you are downloading. the problem with the standard avi preview with kazaa is that the player can be hard to use, and it can onyl preview the first piece of data you have. this means you can have 300 meg of a film, but can only preview 20 secs or whatever.
however, AVI Previewc (ddl) is a command driven avi preview utility. it creates a new avi file which contains all the data you have downloaded before. it can also be played in whatever player you like (so long as you have the required codecs), which is great.
you can find all the necessary information either contained within the program in the readme, or from the site of the programmer, here