Perl is the programming language I have used longer than any other, although not with the same consistent intensity that I have given to VB/ASP. This site is built all on Perl, though I prefer PHP for database-driven pages.
Most of the work I have done with Perl has had more to do with text. For example, I have for more than two years been slowly improving on and expanding tools for posting and editing successive updates to a site that stores its information in text files. One of these is made available to the public through my site FakeTP.com. The script is due for a rewrite because it has in it many vestiges of my earlier days of Perl, but from a functionality standpoint it is quite strong.
A useful tool I made for scheduling.com went to a virus alerts web site, then using Perl copied the site to our server, used regular expressions to extract the portion of the page that we were interested in, then formatted that content for matching presentation on the SCIview portal. Perl makes it easy.
Another useful tool I made in Perl solved a problem I had with a client whose website I host. This person had more than 700 images stored on the server, hundreds of which were unused and left over from news articles long since deleted. There was no practical way for her to review all these images and delete those no longer used in the many dozens of pages on her site. I used Perl to review her log files to make a list of images actually being used, to compare that list to the files stored on the server, then to delete the files that were no longer in use.
My introductions to Perl came from sites like cgi-resources.com (which now includes several tools of mine, including Poster. That site provides hundreds of scripts for download and use by those who wish it. With that introduction to Perl, I have placed an emphasis with many Perl scripts I have written to make the code very simple for others to configure and use.