In this latest post from the Professional PHP Blog, there's a brief compaison of PHP versus other languages on a few different points.
I prefer to group languages in a different way.
Chris Shiflett posted some thoughts on PHP and Ruby on Rails which has generated some interesting discussion. Chris divides programming languages into two categories: Flexible and powerful, Structured and organized.
Among the topics to compare the languages under, included are things like garbage collection, interactive or batch, and abstraction. For each, he breaks the category down, describing what it's all about and seperates it into its two components, assigning langauges.