The places that prefer the long ones are usually the ones where HR is going to be the first department to see it. If it’s going directly to a hiring manager (the situation you want, but not always the situation you can get) you’re probably better off being brief.

And if you don’t know who’ll be the first person to see your resume at a particular company, you haven’t done enough research yet. Do more research before you apply.

The last time I was actually in the job market (and with any luck at all, the final time for my life), I actually maintained 8 different versions of my resume. One long one, covering everything I’d ever been paid for, and most of the stuff I’d done for free which related to things that somebody might someday _want_ to pay me for, and seven short ones, targeted to particular types of opportunities. (I had to customize because otherwise, I’d have to make the print in the skill listing as small as the print in the listing of jobs I’d had, or else go onto a second page.)

http://www.manager-tools.com/2005/10/your-resume-stinks/

Since then, I’ve reformatted and trimmed my resume down to one page and in doing so used it to apply for a job in which I am now employed.