|Don't ask to ask, just ask|
We’ve tried local Perl users groups and other places, but we’ve not been able to get top people.
Searching for job candidates is expensive. Finding ways to reach good Perl programmers can be hard. Getting the good Perl programmers to seriously consider leaving their current job to join your business might be easier than you think.
How supportive is Whitepages of your local Perl user group? Are most of your developers encouraged to attend meetings? Does Whitepages allow developers time to prepare talks to give at meetings? Would the typical SPUG member know that Whitepages was an all Perl shop? Or does SPUG only ever hear from you when you want something?
This message really applies to all Perl shops, not just Whitepages. Support your local Perl user group. Provide a meeting room if there isn't one, encourage your developers to get involved (provide a budget to help transport them there after work or pay for a round of drinks at the pub afterwards), sponsor a visiting Perl expert to give a talk occasionally. This has three big benefits to the business. First you become known as a company which cares about its employees' development. Secondly you become known as a company which cares about Perl. Finally you will help the Perl community in your local area grow, thus giving you access to more Perl programmers.
If your workplace is as fun to work at as you suggest, your employees will spead the word. Then, whenever you're looking for employees you'll have a ready pool of people to invite. Recruitment will become a lot easier and cheaper, saving you money in the long run.
Another possible payoff will be in a mix of employee satisfaction and personal development. If you encourage your employees to give presentations at the meetings, then they'll learn presentation and public speaking skills. If you encourage them to attend, they might learn about new modules, or different ways of doing things.
There are still very experienced (but closeted away) Perl programmers out there who don't know about references. Instead of a hash of arrays, they build a hash of very long strings with separators. They might be otherwise good programmers, but they need to get out more, and find that Perl has moved on a little. Perl user groups help achieve this, and you can help your employees by encouraging them to get involved.
Becoming a regular Perl Monger and a (varyingly regular) Perl Monk was the best thing I ever did for my understanding of Perl. Encourage your programmers to do the same.