ha, found a cross reference... http://www.sparkplugs.com/

can either go by part number OR by plowing thru down to specific bike...

NGK - IMR9C-9HES then click List applications for part number IMR9C-9HES

Motorcycles, Minibikes, Mopeds, Scooters HONDA 2005 CBR1000RR/R REPSOL EDITION 1000
Motorcycles, Minibikes, Mopeds, Scooters HONDA 2006-2005 CBR600RR 4 plugs needed 600
Motorcycles, Minibikes, Mopeds, Scooters HONDA 2007-2004 CBR1000RR 1000

Extreme Long Life Laser Iridium Plug, 10mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Special Firing End Construction, Iridium Tipped Fine Wire Center Electrode with Platinum Tipped Ground Electrode, .036" (0.9mm) Gap

====
NGK - R0409B-8 then click List applications for part number BR9EG-N-8

Motorcycles, Minibikes, Mopeds, Scooters HONDA 2007-2005 CRF250R --- 250

Racing Plug, 10mm Thread, 19mm (3/4") Reach, 5/8" (16mm) Hex Size, Gasket Seat, Resistor, Stud Terminal, Half-Thread Shell, Ultra Fine Wire Platinum Tipped Center Electrode, Fine Wire Nickel Ground Electrode. NOTE: Does not include terminal nut, if necessary, order part #067606-0051
-=-=-=

edit: oops, originally had the CR250 not the CRF ... my bad.