Q:

Grades and years after graduation

What is the significance of undergraduate grades (2.6/4.0) after 5 years of work experience. Do they still carry a value? If your job is not research oriented, e.g. for me I am a software developer on various enterprise Java technologies, how should I project myself to admission committees?
What are your suggestions for me? Getting non degree classes BEFORE APPLYING etc.? Currently, I am in Turkey and I want to enter US Job Market possibly after a MS CS, but if I like I can continue with a Ph.D. So I am an international applicant.

A:

Let me add a few points to aeismail's answer.
Whether your work experience counts as positive or negative also depends on where you apply.  You express interest in a PhD, which suggests that you are aiming for a research masters degree (with a thesis) and not a professional masters degree (just more classes).  These two degrees are very different.  For admission to a research MS program, your non-research work experience is unlikely to count in your favor.  Your work experience is much more likely to help if you apply to a professional MS program.  On the other hand, professional MS degrees are usually considered terminal, not as preparation for PhD.
It is possible to move from industry to a research degree program with a low GPA and industry experience—I did it myself—but you will need strong evidence in your application that counteracts your low grades.  Specifically:

You shold take the GRE — both the general and the CS subject test — and do really, really well, at least in the 80th percentile.  This is direct evidence that you're smart and that you know the field, counteracting the negative evidence in your transcript.  If you take the GRE and don't do well, step back, study hard for a few months, and take it again.  (Yes, this can get expensive.)
Your recommendation letters must imply strong potential for research aptitude, not just your coding ability or your ability to work in a team.  You need to tell your letter-writers to address this issue directly; otherwise, they almost certainly won't.
Finally, you should consider applying to take courses as a non-degree student.

A:

How much grades matter depends on the institution you apply to. The larger the department or company, the more grades will matter, because they will likely be used as an initial screening criterion to "whittle down" the pool. A GPA below 3.0 is not going to help, and at some places, will earn you an instant rejection, work after graduation notwithstanding. 
However, if the review is "holistic," and you have outstanding letters from your recommenders, then the impact of the GPA may be lessened. (It will not be completely overlooked, but at the least it won't be a criterion for "bouncing" you without further consideration.)
I should also point out that after graduating, depending upon who you work for, your GPA may still matter. At a start-up or small company, it may not be such a big deal, but I've worked for several large-scale employers who had rather strict GPA cutoffs (well above 3.0 for both undergraduate and graduate degrees!). If you were way under this level, it was just not in the hiring manager's interest to spend the time necessary to defend the hire, versus selecting a candidate with a better record. So you may be able to overcome your academic record, but you won't be able to bury it completely.

