A thread at HighRankings named Backlinks Anchor Text Could Be The Same? discusses if you should try to get the same keyword or keyword phrase for all of your inbound links. It is of course interesting looking at your backlinks, I developed a Web based application that uses the Google API to analyze the backlinks found within Google, including the anchor text pointing to your pages. I named the tool Google Link Popularity Analysis Tool, but Optilink also has a pretty nice desktop application the queries more then just Google. In both those applications, it is very easy to see how people link to you.
One thing you realize is that the anchor text pointing to your pages are often different. However, there are some links you do control (i.e. the ones you pay for or maintain yourself). I put up a test page on this blog several months ago to test the effectiveness of targeting a single keyword only. I only had links with a single keyword to that page, the page had good content, but again only had one keyword pointing to it. Of course, it had hundreds links with the same keyword pointing to the page. The keyword was very competitive and I achieved top 10 rankings for that keyword phrase.
Does one get penalized if 100% of ones links contain the same keyword? Hard to say, makes for an interesting topic at HighRankings. I have now set up a new test page, in order to test several other factors, one factor is having multiple types of related keywords pointing to the same page. We will see.