Distributed computing for a company? Is there such a 'free' thing?

Corporately we use grid computing for things similar to this. A great one to investigate is Condor.

are those 'cpu intensive things'...

• developed in-house? then you'll have to split and distribute the job yourself. there are some nice libraries, but everything is very low level.
• prebuilt software? then talk to the developer/provider. either it's supported or it's not
• same process applied to lots of individual items (for example, processing thousands of images)? then you might be able to set a simple system out of a DB table holding the subtask status + some batch scripts that: pick a task, mark as doing, do it, return the result, mark the task as done, repeat until all tasks are done.

I think that if you are talking about render farms, there are some examples of such projects.