Brainworx and Plugin Alliance have announced the release of the bx_subfilter, a new plug-in for Mac and Windows which they say is "quite possibly the easiest way to tighten and pronounce a sound's low end".
bx_subfilter is a free plugin that borrows from the "Filter" section of its larger counterpart, the bx_subsynth.
Sign up at Plugin Alliance and you'll get instant access to the bx_subfilter, along with five other free plugins. No dongles, no hassles, and no payment required.