Twitter w/ Perl + serial

All of the twittering interfaces I have seen use the ethernet shield. I am at a premium on i/o and would like to instead have the arduino twitter through the serial port into a perl script. Has anyone done this and have any pointers?

I saw a blog post just yesterday that used serial to interface arduino/python/IRC it may help you... unfortunately, this is my fist post, so they won't let me put a link.... search Google for "IRC and Arduino" it should come up...