Some PM one-liner nodes:

• How does $. work in one liner?
• [Solved]: Thoughts on a section for popular one liners
• search/replace one liners without clobbering
• Process multiple input files using a one-liner
• One-liner only checking the first line of the input file
• one liner append line(s) to matched paragraph
• How to handle metacharacters in input file for Perl one-liner code
• What one-liners do people actually use?
• remember perl one-liners
• Scriptome and Perl One-Liners
• Favourite One-liners?
• How-To on Perl one-liners
• Uncommon* but Useful Perl Command Line Options for One-liners
• Perl White Magic - Special Variables and Command Line Switches
• Escaping characters in one-liners
• another benefit of one-liners
• Re: The problem with one-liners...
• One Liners
• Re: One Liners
• another benefit of one-liners

A new O'Reilly book dedicated to Perl one-liners:

• Perl One-Liners: 130 Programs That Get Things Done by Peteris Krumins

Some non-PM Perl one-liner tutorials:

• perl.com article by davorg: Perl Command-Line options
• merlyn's first unix review column
• Hot Perl oneliners
• FMTYEWTK About Mass Edits in Perl
• YAPC::NA 2008 talk on Perl one liners by Walt Mankowski
• Peteris Krumins, Famous Perl One-Liners Explained

• Cultured Perl: One-liners 101 (update: broken link)
• Cultured Perl: One-liners 102 (update: broken link)
• cog's "Perl White Magic" talk (update: broken link)
• petdance field guide to the Perl command line (update: broken link)
• merlyn sysadmin article (update: broken link)
• Perl One Liners (update: broken link)
• Some TPJ one-liners (update: broken link)
• Perl Limericks (update: broken link)