Resumes

What exactly makes a good resume? Is it length? Is it formatting? Is it content? Is it all of those, some of those, or more?

My company is currently in the middle of a merger/aquisition and as a result I've been putting together my resume. I read numerous online articles about writing resumes, looked through several co-workers resumes, read some book in the store at Barnes & Noble about writing resumes, and had my resume reviewed by several co-workers, former employers, and multiple HR professionals.

I've found that there some commonalities between all resumes, and then a bit of a different focus for technical resumes versus management resumes, etc. I'm still not happy with my current resume, but I think that resumes are always a work in progress.

It's been 6 years and two companies since I needed to update my resume, so needless to say I've done a lot in that span of time and trying to highlight everything that I did to capture peoples attention without taking up too much space and making the resume overwhelming is a huge challenge. I don't have time to post about all of my discoveries right now, but I plan on going into what I've found soon, and I'd welcome any feedback as well.