Mr Cool XXX,
If you havent heard from then even after applying at20-30 of them, your resume is still sort of something, or they way you applied.
I had gone through the same phase, and I would advise you to take care of the following things:
1. Only apply at requirements which match 90% to your resume.
2. Change your resume a little bit to make it job and role specific. Dont forward same resume & cover letter to 20 different companies.
3. Indicate in the Cover letter why you are applying to that particular company and not others. You have to research the company you are applying to, and know their strengths and attractive points, objectives anad goals and make sure you include those points in your resume.
4. Make the cover letter as personal as you can.
5. Follow up after a week you apply.