Yes, you can do that with AdWords’ Dynamic Keyword Insertion feature. This post will explain how to do it:
Google Adwords Dynamic Keyword Insertion PHP Script | Dave Wooding
It is simple enough for anyone with a little basic PHP knowledge. There are likely a few plugins, I just never looked because it is easy enough to do without a plugin.
Having said that, You would probably be better off putting effort into improving the CTR of your ad since that is the primary factor in your AdWords Quality Scores.
