I couldn’t have said it any better than Nick Usborne over on his Excess Voice blog. Rather than repeat what he says, go over there right now and read what you shouldn’t try to do when it comes to keywords and writing online copy.
It’s really just common sense, if you are writing on your core topic, you will naturally use your key words. You don’t have to do anything else. You can’t trick the search engines, and you really don’t even need to try. Just stay on topic and if you do stray, just tie it all together. There is a reason you are writing, and a reason your readers will read. Just repeat that in your posts, your newsletters, and on your web pages.
So you can get a little clever in your article and blog titles, but just make sure the title says what it delivers.