How many times can you update/change a resume?

I have written and rewritten my resume more times than I can count. In an effort to find a job (or, at the very least, garner some interest or secure an interview), I just finished updating my resume yet again. Hopefully, the thirty-seventh time is a charm. With a tweaked resume, I can finally start applying to the list of various jobs that I bookmarked over the last couple of weeks.