I've released a Perl wrapper for v3 of the API. It covers all the API calls.
You can find it here http://search.cpan.org/~jeffery/Net-CampaignMonitor-0.02/lib/Net/CampaignMonitor.pm
It has only just gone up so it may take up to 24 hours to appear in your nearest CPAN mirror.
Please let me know of any bugs/errors/ommisions.
Jeffery, this is brilliant. Many thanks for keeping us updated!
For the benefit of everyone here, this has been added to our library of API wrappers.
An update - the following is a better URL than the one I gave above (it will always list the latest version) http://search.cpan.org/search?q=net::campaignmonitor;s=1
Or just go via CM's library of API wrappers.