After a year of unemployment, five months of really serious jobhunting (after I finished my MCSE), and exactly zero job offers, I got two good job offers on 23 February 2000. Both job offers came after I responded to advertised jobs on the websites that I have listed above. Note that I had been rejected by both companies a few months earlier for the same jobs! I accepted one of the jobs, so this page will not be changing much anymore.
Check the job websites at least four times a week and respond immediately. If you see a job you really want, email a response and then also snail-mail a cover letter and resume. Email is unreliable.
Don't depend too much on recruiters. I only found one headhunter with real jobs. All the others were just collecting resumes.
Mail resumes to companies that hire people like you but haven't posted job openings. Many jobs are filled without being posted if the employer already has a resume from a qualified person on file. This save the expense of an advertisement and also the hassle of sorting through 300 resumes received because of an advertisement.
Be persistent. If you really want to work at a company, keep sending them resumes and write thank-you notes after each interview. In both cases I was rejected the first time they advertised the job, then accepted the second time they posted it when I sent in another resume.
Follow up. If you talk to an employer at a job fair, and they say "call me in a week", then call them in a week. Some employers only look at the resumes of the applicants who seem really serious about wanting a job at that company. If you call them when you are supposed to, then your resume gets moved to the "serious" stack and gets a look.
Good luck! The jobs are out there if you have the ability and are persistent.