I sent a zillion resumes out to ad agencies a week and a half ago. Most of them didn't have job postings, but I was sending my resume to express interest in their company. Of course, I haven't heard from any of them (surprise, surprise). Should I send follow-up e-mails? Or should I just forget it?
I think you absolutely have to follow up. Most companies these days are flooded with resumes, and if you don't show some initiative by contacting them, then they'll assume you're no longer interested or aren't the type of person to work for them.
I agree that you should call them. I think calling is the best option because hearing someone's voice on the phone is much more personal than receiving an e-mail.
I would ask them 1) if they received your resume 2) had a chance to look at it yet 3) ask if they have any available positions that could use your talents and if not, then 4) ask them to keep you in mind for any future openings.
Don't lose hope, Nylabelle. You'll get a job. It might not be today or tomorrow, but something better for you is out there and you'll get it. You just have to hang in there and keep trying. Keep us posted on the interviews and everything! And if you want another opinion on your resume/cover letter feel free to PM me.