I agree with Adamah and blankslate.
snit, you've got a great profile, and you should definitely be applying. In my opinion (and in Matthew Might's), if you haven't published, you need to prove that you have the interest, experience and potential of doing research. A published paper demonstrates all of that, so it's useful, but it isn't necessary. If you can demonstrate interest, experience and potential effectively through some other things you've accomplished, you're good to go.
In order to do this, you should have specific goals in mind about what you want to pursue through a master's. You should choose a specialization, a research area or a topic that you have had experience with (through a project or through your work), have shown interest in it (maybe by doing something independently) and hence have tangible potential for.
Look back at all the work you've done (projects, research work, your current work) and try to find a common interest or a theme in it. Try to find some progression and some direction in your choices. Then look through university and professor webpages to see what work is being done by them, and see if your interest or your experience matches with it or if you could contribute to that work because you've had some experience related to it. The best match would be something that you have had experience with and is a step forward in your direction. At this stage, it's good to get in contact with Professors and check if they are interested in you.
If you're able to convince professors (through your Statement of Purpose) that you can contribute to research or the work being done at that university, you will have a better chance of getting admitted.