Apologies for the long post, just found this interesting as I'd been wondering about this guy myself.
Just did a little searching and found quite a lot of rent a quote mentions of our Frank. I tried to look for a web address for the INUSA but nothing doing or any email address to contact but nothing. They aren't registered on any supporter sites I can see. I looked at other names mentioned in conjunction with the INUSA, but only Kevin Miles and John Regan were mentioned. They seemed quite active in the 90's, as NE5 said regarding the SOS campaign, but seem defunct this decade, bar the constant quotes from Frank .
http://www.thisislondon.co.uk/sport/article-23486003-details/Fans'+review+of+the+season:+Did+the+earth+move+for+you/article.do
Frank reviews last season.
http://news.bbc.co.uk/sport1/hi/football/teams/n/newcastle_united/7122616.stm
However, Barton's comments prompted an angry response from Frank Gilmour, chairman of the Independent Newcastle United Supporters' Association.
http://www.dailymail.co.uk/news/article-1032693/Bin-Ladens-family-set-launch-bid-buy-Newcastle-United.html
Frank Gilmour, of the Independent Newcastle United Supporters' Association told the Sun newspaper: 'It's disgusting, an absolute joke.
http://www.dailymail.co.uk/sport/football/article-1052643/Toon-army-threaten-boycott-Newcastle-line-Spurs-assistant-Poyet-replace-Keegan.html
And Frank Gilmour, chairman of the Independent Newcastle United Supporters’ Association, added: 'I would expect the lowest attendance at St James’ for a long, long time at the next match,'
Other mentions of the INUSA
http://www.imusa.org/about.php
The Independent Manchester united Supporters' Association was launched in April 1995 at an impromptu meeting in the Gorse Hill Hotel....
Thousands of leaflets were distributed at the last two home games of the season advertising IMUSA's existence and the next meeting, at Lancashire Cricket Club on 11th May, took place in the week before the final game of the season at West Ham. The meeting was packed out with hundreds of Reds who listened to Kevin Miles from the Independent Newcastle United Supporters Association describe how they had set up their organisation and the experiences they had had in dealings with NUFC.
Dec 15 1998
http://news.bbc.co.uk/1/hi/business/the_company_file/235443.stm
Kevin Miles of the Newcastle United Independent Supporters Association, said: "Nobody should be under any illusions that any company comes in to buy a football club as a favour to ordinary fans."
There is Kevin Miles, a toon fan, who has been International Co-ordinator for The Football Supporter’s Association since the 1998 world cup (email addy in the whos-who section).
http://www.fsf.org.uk/whos-who/fsfcontractors/kev.miles.php
due to give a talk in april 2009:
http://www.ncl.ac.uk/peals/news/events/item/cafe-politique-the-politics-of-football-will-elitism-ruin-our-game
More INUSA In 1998:
http://www.telegraph.co.uk/htmlContent.jhtml?html=/archive/1998/03/16/nnu16.html
John Regan, secretary of the Independent Newcastle United Supporters Association, said yesterday that he was staggered by the allegations, adding that, if true, "this has to be a resigning matter. They will both have to go and they must go quickly".