Ways of landing an interview in tough times: From someone who has landed jobs and also recruited and hired in difficult economic times (not to repeat all the info on the web, but here are some tips that I know work - most applicable to white collar jobs):
1. If your resume is not accompanied by a very specific cover letter (one that lines up your skills with the job advertised), your odds of making it to the top of the pile are slim. Remember: The hiring manager isn't the one scanning for qualified applicants, it's usually an admin person. Make it easy and make it clear you are 100% qualified (create a matrix of the skills required vs. how you satisfy them). You'll increase your odds of making the short list.
2. If a job posting has a fax# (or you can look the company up and find their fax #), fax your resume and cover letter. People rarely do this, and a hard copy will be get more of a glance than an electronic version. Write a handwritten note on the cover page to personalize it.
3. If the job posting has a hiring manager and phone number posted (rare, but it does happen), take the initiative to call (PLAN what you are going to say beforehand!). You might catch them off guard, but you'll be remembered when resumes are being reviewed (and make sure you're remembered for the right reasons - that's an entirely different topic!).
4. Communicate the value you've provided in past employment, and the value an employer can expect. Don't just put together a chronological resume that states "did this, did that". It should be more like "did this, and the benefit was X". It's hard to do, and most people aren't comfortable with it, but it makes a difference. You have to WOW employers (you're one of many desperate for the job).
5. Toss away the notion of the one page resume. Unless you know the hiring person, it's not necessarily a good thing if it prevents you from telling all of your valuable history. Instead, write a rock solid cover letter that is very concise (see item #1). Whet their appetite, and they'll look at the remaining detail.
6. Rather than respond blindly to any opportunity with a generic approach, take control of your job search and get organized. Make a list of the companies you would like to work for and research them. Read their financials online (Yahoo business, for example) and read their executive bios. Create your case for why they should hire you. Then, start to find a way to get into that company (see next item).
7. The approach to getting an introduction to a company will vary between white collar and blue collar. A walk-in isn't unheard of in either case and might work best for blue collar jobs. Believe it or not, if your proposition is compelling enough, you can get a second look with an email subject line that grabs their attention. For example, I landed an interview once by emailing the CEO of a former competitor that read something like "Used to compete with you and never lost". Getting the CEO's email address was via simple guesswork (I researched the corporate website, used google, and once I found the naming convention they used, took a swag at the name and sent it off). Sometimes, it is best to email a VP since CEO's often have their email scanned by an admin (VP names and bios are usually listed in the "about" section of a corporate website).
8. Do your homework - if you have a name (either provided through networking, research, or an arranged interview), learn as much as you can about that person on the web and find a subtle way to relate (for example, if you find they went to Penn State, and you did also, it's a means to make a connection). Spokeo has proven very useful in researching business contacts or job applicants (although, there is an annual fee).
9. Research your web presence. THIS IS HUGE. An employer will - at a minimum - google your name and look for any dirt on you, and how you present yourself in public. I've researched nannies and job applicants this way and 50% of the time, I find something that puts me off. Example: Constant use of the "F-bomb" on twitter; photos with a recurring partying theme (i.e., all photos with alcohol in your hand); any photos that show you in "less-than-classy" attire or situation; Twitter posts that make it sound like you don't have it together. Clean up your web presence NOW. An employer most likely won't tell you what they find if it's negative, but they will just fall off the radar. Also, create a NEW PROFESSIONAL sounding email address for all job related communications (a new account won't have any links to any past social sites you may have created a profile on). Additionally, find ways to get your name on the web as a subject matter expert (sign-up for user groups, bulletin boards, etc. and post advice on a regular basis - make sure it's able to be linked back to you via name or email address). Make sure everything you post on the internet puts you in a positive light.
10. Develop a "Try it before you buy it" proposal. Come up with some compelling and creative way for the hiring manager to try you out. It can be a challenge (like "review our website and recommend improvements"), or a fixed amount of time (there are some cities offering a program for the unemployed to work for free for 30 days, with the option of retaining the person after that period.....many are retained). What do you have to lose except time (which you have plenty of, if you are unemployed). At a minimum, you might learn a new skill, or get a great reference out of it that can help you bridge to a better opportunity. Here is a great article about someone who used this approach: http://www.careerbuilder.com/Article/CB-1360-Getting-Hired-Try-Before-You-Buy-How-to-Get-a-Job-That-Doesnt-Exist/