COM confusion. When should I use it?

I've been learning about COM in the last few days, and I can see how powerful it is, but I don't really know how often or even where I should use it. Could someone give some examples of when it should be used?

The best place to use it is where you have a piece of code that may be used by another language. For instance a file leech program written in C++ that can be invoked from VB or a VB front end package that can be scripted with VBScript...etc

Hmmm I never do that sort of thing. Maybe it's not for me.