I've now applied for 54 jobs, all of which I am fully capable of doing.
Makes you wonder doesn't it, in terms of just how many stellar CVs are companies seeing hit their inboxes when more than 9 times out of 10 you can't even land an interview for jobs you feel you are capable of. We constantly read in the media about the skills shortages, about how companies just can't get the staff these days (especially graduates), yet seemingly suitable candidates never even get a look in.
Obvious point (apologies if already done) but maybe worth giving your CV a once over and getting some second opinions on it, it could be that you are indeed capable of doing these jobs but your CV just doesn't convince the person sifting them most of the time.
Oh, and I agree about lack of response being frustrating in this day and age. A simple "we have completed our sift and all candidates for interview have been notified" would suffice, this could be a blanket email to everyone who applied, at least you know where you stand then.
I know some people have a rule of thumb "if you haven't heard within X time then you won't get interviewed" but it varies a lot between companies, I remember one job I applied for about 6 years ago it took 6 weeks between my application and them contacting me to arrange an interview. I'd actually moved house inbetween!