I bet you are eager to find out just how to do this. "Spamming Google" that is, and grasping away with it. Maybe you want to try this method out or maybe you are another SEO guy waiting with baited breath to downplay this concept.
Well, I hope you are ready for the answer regardless.

First, lets go over what is bad Spam. Im not entirely sure that there is sizeably workable spam, but for arguments sake, lets discuss what you shouldnt do.

Spam means (according to www.answers.com), Unsolicited electronic mail , often of a commercial nature, sent indiscriminately to multiple mailing lists, individuals, or newsgroups; junk electronic mail . Now, search engine spam is different. You may spam by repeating keywords too many times in your sites content and tags. Hiding writing on web pages is also spam. Creating a lot of back links to bad neighbors is yet another example of spam. You can also spam by:

Using bad re-directs
Using doorway pages
Cyber squatting
Using micro/mini sites. (sites with 3 or less pages)

Now, I do not support spam, nor do I participate in it. If you come across a site that is spamming, you can and should report them. To report to: Google http://www.google.com/contact/spamreport.html MSN http://feedback.search.msn.com/default.aspx Yahoo http://add.yahoo.com/fast/help/us/ysearch/cgi_reportsearchspam

The type of spam you CAN get away with is content. I understand what you are going to say... "Content isnt spam". It is, I assure you. I write 4 articles a month. I submit them to approximately 130 sites per article. Thats over 500 links a month. That is a tremendous amount of links. However, Google does not see it as spam. This is the only form of "Spam Google permits. Those 500+ articles all create valid backlinks. Thats all the search engines accept. There may come a instant when the search engines may evaluate these articles to see if they are of real" content and not generated (which mine are, so no worries there), but as of now, this method is acceptable.

Another way to use this content is with blogs. Search engines tend to favor
blogs over websites. Writing keyword rich content can help pull in some traffic. Remember, choose the title of your blog intelligently as this may generate or break your blog. Be sure it is a keyword phrase that describes your content in general. You may create as many content rich posts as you would like. The trick is that the content needs to be real content. The keywords should be at least 5% of the overall content. The name also needs to be optimized. I do not advise anyone to write content solely for the sake of having a place for keywords. Think of why you want those keywords to exist and you now have something to say.

You might disagree that this is spam, but indeed it is. I wrote an article earlier this year titled, "Out of Exile: How to get un-banned from Google". On Yahoo, nearly 3,000 sites have pick this article up.
http://search.yahoo.com/search?p=%22Out+of+Exile%3A+How+to+get+un-banned+from+Google.%22&ei=UTF-8&fl=0&xargs=0&pstart=1&fr=FP-tab-web-t&b=91
Under any other circumstance, this would be bad SEO. Since this is content (and content that has certainly helped out quite a few everybody from the feedback Ive received), it is allowed. 3,000 links in a few many years is spam. No doubt about it. So, Spam away.