Combining music or video files?

[John Salerno]

Before I try this and destroy my computer :) I just wanted to see if 
this would even work at all. Is it possible to read a binary file such 
as an mp3 or an avi, put its contents into a new file, then read another 
such file and append its contents to this same new file as well, thereby 
making, for example, a single long video instead of two smaller ones?

Thanks.