Draxil, I tried to run your code, but it appears (after searching CPAN) that Gtk.pm is only availble for Unix (I'm on Win) so I couldn't test your code. I'll leave it up to you to determine if it works correctly. So I'll list some suggestions instead just from browsing through your code.
You should use #!/usr/bin/perl -w to turn on warnings. This is a comment that many monks suggest. It helps in debugging, so it's always a first step.
You should use strict; which will make sure that you are using 'clean' Perl code. (Again, this is something that almost every monk will tell you is necessary/manditory.) You will probably have to add a lot of 'my' declarations to your variables (ie: my $http= new HTTP::Lite;) to elminate some errors.
I'm not so sure about this point, but I know that I personally wouldn't use the variable $pack since pack is a function of Perl and described in Perlfunc. I guess I'd be leary of using such a variable... again this is a personal choice.
When you use your or die statement, make sure you include in your error message $! to include the system error messages, in addition to your message (ie: or die "Couldn't retrieve the Word Of The Day.$!";.)
I like the fact that you commented your code. It's easy to follow and the logic makes sense. I think the code is really good for being 'half asleep.'
Please keep posting code and participating at Perl Monks. I learned a thing or two from your code just by doing a read through. If you have questions, post them, and if you have some help for someone, feel free to participate Draxil. Welcome to Perl Monks.