Should you send your resume in a PDF or word format?

BOTH would be my answer.  You probably set up your resume in word and then created a PDF file from it.  So why not send both and here's my reasoning.

PDF files are used because it gives you an exact picture of the way you set it up. This way all your text boxes, graphs, and pictures will stay lined up the way they were formatted. The problem appears when you are dealing with a company that wants to "tweak" your resume before they send it to their clients. Recruiting companies like to enhance your resume with little things like highlighting key words or more major things like removing all the "I did" and changing them to action words like "designing, developing, etc". They know their client's specific needs and want to make sure these points are clear and concise in your resume.

PDF files can be very difficult to copy into word documents. I have seen files copy over and put one word on each line. This can then mean a total retype, which takes time and time can sometimes be the difference between having your resume processed or not.

Word documents are easy to revise and search on. Recruiters will take your resume and put it on their letterhead for presentation to their clients. Companies receive so many resumes that recruiting agencies have standardized their resumes so that when their client looks at one of their resumes they know exactly where everything is, ie Education at the top, followed by Technologies, followed by Professional Experience.  This allows HR to quickly glance at the resume and make sure that the key ingredients are there.

So be efficient and send both a word document and a pdf file (if you are worried about the layout).