There are tons of people out there, all developing their own methods of increasing fuel efficiency. From adding Hydrogen to the air stream to fuel catalysts, you will find many many things to try. Some will work, and others... Well, you pay your money and you take your chances, right?
What follows here are technologies that I have personally tested and found beneficial to our common purpose: gaining more power from your fuel. Right now, I am supporting one in public, as I research others in private. If you know of a technology that you have found successful, then let me know. I will take the next step and do my best to check out the technology and report on it here.
The MAPster
The MAPster was designed to correct the signal sent to the ECU from the MAP sensor. This device will assist in stabilizing mileage gains on any Voltage-Based MAP and comes with complete installation and adjustment instructions.

It's not only the most effective way to increase your mileage after the Gadgetman Groove modification, at only $50, it is affordable, too!
Click here to order one for your vehicle.
Bear in mind that most (if not all) this technology was designed and is marketed for HHO Developers, their use is in perfect harmony with The Gadgetman Groove modification.

I have personally installed several of these units on everything from Toyotas to Pontiacs and beyond. What impressed me more about Fuel Saver was Mike Kerhli himself. After following his relationship with various clients over a period of three years, he has established himself as a genuine and caring developer.
He will do whatever it takes to see you get everything you expect, and more.
Check out their Quad Digital EFIE Basic.
I personally guarantee you will be happy.
Mike has also developed several other technologies to allow for greater personal modulation of various sensors.
Be sure to check out his MAF/MAP adjuster, as it is the ONLY one I know of that will work on both the analog style and those blasted Freq based MAPs on Ford Products!
CANADIAN GADGETMAN
J. BRUCE McBURNEY'S HIMAC RESEARCH
Many people have impressed me with their research and development, but none more than J. Bruce McBurney.
Through special arrangement, Bruce has cordially agreed to offer all Gadgetmen a 25% Discount if you simply use the word "Gadgetman" in your order.
With his passion for Freedom for Mankind from slavery to energy demands, he has done MUCH to advance the understanding of what the mainstream considers "Fringe Science". We in Gadgetman Land simply consider it a way of life!
He has posted a number of documents that are well worth reading, all FREE at his Documents Section.
When you're ready to share a little wealth with Bruce, you are going to find his product section well worth the visit! Anything you get through him you can count on doing a LOT of things at once. You will be gaining in understanding of something new, spreading technology that would otherwise be less valued AND you will be feeding one of our brethren!
Don't expect a lot of SIZZLE to his information, or a lot of different products. He is a specialist.
More importantly, he is a FRIEND.
Bruce McBurney's Products Page
Remember to take advantage of the 25% discount by telling him you're a Gadgetman!