Looking for a package filename expansion in a buffer (ala dabbrev)

[bigfaceworm]

All,

I'm sure someone has written this, but my google searches have turned
up nothing.

I'm just looking for a package that will let me expand filenames when
I'm inside a buffer.

   e.g.  I'd be typing /a/path/to<KEY>

and KEY would expand (or give me options) the path/filename

   /a/path/to/a/unique/file

or something like that.

Just trying not to re-invent the wheel.

tia,

BFW