I missed Jet Fretz from this year’s NAMM show. It’s not often that you hear about “breakthrough fret technology,” but maybe this is the real deal. I’ll let you decide. The theory behind Jet Fretz is similar to that of scalloped fretboards: since your finger doesn’t quite touch the fretboard when you fret a note, you get less deadening and more sustain. Also, by seriously increasing the mass of the frets, you increase the mass of the fingerboard and thereby increase sustain.

This from the Jet Fretz website:

Jet Fretz are the newest technology on the market!
Nothing enhances your playing like extended sustain and Jet Fretz delivers that sustain unlike never before! Stand out from the crowd of players and bring them to their feet with Jet Fretz! The dovetail base slides into a specially slotted fret board.
Higher mass & stabilization plates on the frets create as much as 35% more sustain to your instrument.
Jet Fretz are available in different height sizes, so if one night you want a scalloped feel, no problem!  Check out the pics of our radius version frets.
Jet Fretz are made of stainless steel so they won’t wear out for a long time!

Here’s the NAMM vid from PremierGuitar.com:

Unfortunately, the Jet Fretz website is a little sparse, but you can get the general idea. Check it out.