I am not so sure about that - according to
ASUS at http://www.asus.com/support/cpusupport/cpusupport.aspx
then query by Motherboard
they say that
Athlon XP 2600+(266FSB)(Model 8)(Thoroughbred) 1.07 1011
is supported - but for the life of my I can't figure out if this is a Mobile Athlon XP or what.
The biggest problem that you are likely to encounter is caused by the way Mobile's multipliers are set, they'll natively boot at 6x, the BIOS will be stuck in the 5x-12.5x range, making it difficult to set anything in the 13x-24x range.
You can work around this limitation either by cutting bridges or by using a software tool that will trigger the PowerNow! states, enabeling you to set an appropriate multiplier, otherwise you'll be stuck with an underclocked chip.
Newer motherboards won't have any problems dealing with Mobiles but that would beat the purpose of spending money on an already outdated platform, you would be better off grabbing a nForce3 Socket 939 and a 3000+ A64.
Watercooled Mobile Barton 2500+ @ 2.6GHz (200MHz x 13)
Abit NF7-S V2.0
2x 512MB of Samsung TCC4
Sapphire Radeon 9700 128MB @ 360/310
2x Maxtor 40GB 7200RPM RAID-0
Almost all desktop boards work (to varying degrees) with xp-m chips. Your board will work, just not at full speed. It will default to the 6X multiplier and 133 fsb. An 800mhz chip may not be what you are looking for.
If you can get your hands on an xp2400+, that's about the best you can do. The xp2600 that is available, wont run on your board. (it is a barton, with a 166mhz fsb)