According to this post on Freelancejob.com.au, the results of a statistical analysis of the job postings from getafreelancer.com show a huge surge of PHP jobs being posted.

According to statistical analysis of the 27750 freelance projects on getafreelancer.com site most wanted types of job are PHP (40% of all projects), Web Design (31%), Graphic Design (16%) and Flash (14%).

They provide both the table of the stats generated and a graph clearly showing that PHP jobs are head and shoulders above the rest.