Need to know OPN to get a better idea of what it is. It's either a Palomino, Thoroughbred A or Thoroughbred B core.
Basically it should run in most desktop socket A boards supporting at least 133fsb.
Fab51 has some useful info
http://fab51.com/cpu/guide/opn-xp-e.html
Also list of mobiles
http://classicplatforms.com/cpu/amd/mobile3.html
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MSI K7N2 Delta2 LSR|35w XP-M2400 11x214 1.62V|2x512MB OCZ EL 2 2 2 11 2.9V|9600XT|Seasonic 350w
Abit AN7|XP-M2800 10.5x227 1.62V|2x512MB Mushkin XP4000 2 3 2 11 3.2V|9600XT|Seasonic 550w
Asus A7V600|XP-M2600 6-11x202 1.6V|2x512 Crucial PC3200 2.5 3 3 9 2.7V|PCI 32MB gfx|Corsair 450w