I thought I should submit my version of a logo for your site. Being a Greek geek (how cool is that! ;-), I was inspired by the Greek origin of the word "meta" (=after). Its Latin equivalent is, of course, "post", which was regularly abbreviated in medieval manuscripts as p̅ (that's overline combined with p, if your Unicode support is not up to the task of displaying that) and is even to this day used in this manner in medical prescriptions. The close proximity of the letters comprising the word "cpan" denotes metacpan's role as a website that brings perl users together, encouraging cooperation. What's more a dash on top of letter "p" emphasizes the perlish nature of the site.
However, I think that the best attribute of this logo is its TeX-like properties. It is text based and thanks to modern Unicode it can be incorporated in Unicode based documents, like this:
CP̅AN is a free, open search engine for the CPAN, which is an ever growing archive of code and documentation for the Perl programming language. CP̅AN is a community effort. On the surface, CP̅AN enables the CPAN to be searched more easily. However, because CP̅AN is driven by a free, open API, it encourages the incorporation of this data into many other projects.