What "perldoc" are you using?

$ perldoc -v '$.'
Ending switch processing.  Args are [$.] with 0 errors.
/usr/bin/perldoc => Pod::Perldoc v3.14

Formatter class Pod::Perldoc::ToMan successfully loaded!
Will format with the class Pod::Perldoc::ToMan
Searching for $.
Looking for $. in /usr/bin /etc/perl /usr/local/lib/perl/5.8.8 /usr/lo
+cal/share/perl/5.8.8 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.
+8 /usr/share/perl/5.8 /usr/local/lib/site_perl . /usr/local/sbin /usr
+/local/bin /usr/sbin /usr/bin /sbin /bin /usr/games
No documentation found for "$.".
[download]

Update: ferreira has /msg'd me to tell me it's a feature added in recent developer releases. Nice; it's certainly something I've often wanted to be able to do.