There's something to be said for communication style. You can do essentially what top-GP suggests, but without the high-conflict ultimatum -- basically, communicate your worry about your salary in a series of low-drama conversations, in which you can calmly suggest that your research implies that you'd be able to make $X in a similar job elsewhere, but really enjoy your current job, etc.

The key, of course, is always to understand your BATNA: Are you actually willing to leave? You can play a significantly more daring game if you're prepared to lose, rather than accept status quo or a modest improvement.