I never did get my masters, my graduate grades where poor (did half of a masters and got excellent grades there though). I have never had problems landing jobs, 28 years old and earning over $100k.
Having a diploma shows you know how to read, it shows you know how to learn - these are important aspects of a company. Having experience working is also great, but fact is, every time you switch job you are in for a period of relearning - everything they do will be different from whatever you have done earlier.
First problem anyone needs to get past is being sorted out before interviews, writing resumes is a science, but it isn't that hard, there are excellent resources on how to do this, but in my experience, have a generic CV you attach to a personalized e-mail. In the e-mail write why you think you are good for them, but also very important, why you should work for them in terms of what you expect. Keep the CV short and to the point, I've been through hiring people and christ some people attach a lot of meaningless shit.
When you have landed the interview, be prepared! There are a lot of standard questions you will be asked:
http://datsi.fi.upm.es/~frosal/docs/25mdq.html
those 25 suggestions have served me well through my short career. Never lie during the interview, if you have shortcommings, mention them, tell them how you are aware of them and work on them. Show them you are aware of how business works.
Oh, and make sure you look clean. I know a lot of nerds thinks suits are evil, you don't necessarily have to wear a suit, check up on the dresscode at the company - but looking clean is important, if in doubt a nice shirt worn casually with jeans should be nice and neutral.
Also, Office Space while being exaggerated, does have a few points. Hiding in a cubicle will get you fired, showing you have balls and a meaning will often get you promoted - provided you use them at the right time.