I've been asked this question a few times, and needed to respond:
How long should your resume be?
My answer, which is based on general advice from many books and sites, as well as my experience hiring people is that you should keep the actual resume that you send to people to 2 pages or less. Try to fill out most of a page, but don't go beyond 2 pages.
The biggest reason is that it's annoying for the person reading the resume. We tend to scan them as electronic images, or in Word, but most people get annoyed by having more than 2 pages to read. We move through them more quickly, so you can go beyond one page, but more than 2 just takes too much time and it isn't concise.
I'd really suggest that you try to keep it to a page or page and a half, and if you include keywords, put them at the end so they can be skipped. That way you don't annoy the reviewer. Chances are they get hundreds of resumes for positions so any reason they have to trash yours will likely be used.