This led me to wondering which products worked, which didn't, what options there were for making your own, and ultimately which solution gives the best 'bang-for-your-buck' (no pun intended ofcourse).

Good old Google research turned up the following interesting reading. Some of you guys may be familiar with this subject already... if so, I'd welcome your comments and experience.
Octane Booster Comparison (1999 Fast Fours Mag) (Reproduced with permisison apparently)
http://members.rennlist.org/951_racerx/OctaneBoosterComparison.html
Homemade Octane
http://www.clubwrx.net/forums/showthread.php?t=44006&highlight=homemade+octane
Cheers,
Decuer.