Here it is straight from the horses mouth: Google ignores keyword meta tags.  This has been the case for many years, but some search engine optimizers still use keyword meta tags for smaller search engines.  Using keyword meta tags is in no way harmful, but they won't help you with Google.  Here is a video clip of Matt Cutts from the Google Quality team saying it in his own words:

Google is going to start providing links to relevant page sections intheir search results.  These are going to be done algorithmically sothere is no way to manipulate them.  However, Google recommends thatpages with lots of content should have a table of contents that linksto various sections of the page.  This along with a descriptive anchorat the beginning of the section will help to increase the likelihoodthat a page's sections will get listed below the main search result forthat page.  The section anchor will likely provide thecontent for the link on the Google search result page. 

The benefit to searcher is that they can find content relevant to theirsearch query without having to scroll down the page. The benefit to thewebsite publisher is that searchers will be more likely to click to apage if the link appears to be more relevant.