"Ad-hoc webserver" for static files on UNIX/MacOSX?

Is there such a thing as a tiny little webserver that I can invoke from the command line that just fetches files from the local filesystem and serves them via HTTP on specific port?

I'd like to be able to do something like this:

$ cd ~/Sites/mysite
$ serve . 10.0.1.1 8080

This should fire up a webserver that listens on 10.0.1.1:8080 and serves files from the current directory (".") – no PHP, ASP or any of that needed.

Any suggestion greatly appreciated.