in reply to Just starting Perl
1) As stated above, it's not about what you do, it's about how you do it, and Perl is all about "Easy things are easy, difficult things are possible." As far as advantages over PHP, you'll find a great friend in CPAN, which holds solutions to 99.9% of common problems and a shocking number of obscure ones too.
PHP's benefit is "super easy deployment." It's practically married to MySQL, almost all shared hosting has it, you can start writing a database driven web application very quickly.
Perl is a little harder, as less shared hosts have it, but you are rewarded for your efforts with more power under the hood. For example, PHP has deep MySQL integration, but with CPAN modules and Perl you can easily interface with almost any way of storing data imaginable.
Speaking of data, a good example of power delivered easily is DBM::Deep, which you can find on CPAN. It seamlessly ties your data structures to a very fast flat file database that supports transactions. It has found a home in many of my projects I would have used something more complicated for in the past. See also the modules for easily parsing CSV, XML, and other common formats (aren't all our lives better when we never have to write code to parse CSV again?)2) Also as stated above, you can write a GUI application with Perl, but it really isn't Perl's strength. I often end up doing all of the messy stuff in Perl (data extraction, analysis, output) and the visualization in something else. Your mileage may vary.
Edit: Everybody is mentioning CPAN as the magic (and it is magic), but the Perl language brings you a lot of power itself. You said that Perl syntax looked a lot like PHP to you, and it is true you can code Perl in much the same way as you do PHP (or C, or ...). Perl gives you many options as to how to code. As you learn more Perl, though, you'll start to pick up some very powerful Perl idioms and Perl ways of doing complicated tasks with very little code. Take a look at some of the solutions posted by the veterans here in Seekers of Perl Wisdom for examples.