ANY P4 would be a far better solution than just about ANY celeron. But I'm not sure mobile P4s (or celerons)will work, someone else claimed it won't, I don't know, could be true.
Anyway, if I'm not mistaken, your board supports 800 MHz FSB, so there is nothing to stop you from buying a cheap P4B or C, or maybe even the 2.4 P4E and overclock the hell out of it. Even without overclocking, you'll get a spectacular preformance increase because the Celeron is such an incredible piece of [-peep-], regardless of its clock. A celeron, even at 2.6 GHz, performs on average about half as good as a barton 2500+, and it gets utterly destroyed even by a Duron 1.6. Its probably considerably slower than a good P3 on a lot of things. Avoid it, at all costs (including free).
OTOH, if you overclock a P4B/C 2.4 or P4E 2.4 to ~3 GHz -which should be pretty easy, you would actually be increasing your performance roughly by a factor <b>3</b>. I wouldnt hesitate a second, get a P4 since you already have the MB. Don't ever, EVER buy a Celeron (unless perhaps the Banias based Celeron-M). Even if you overclock it to over 4 GHz, it will still be a piss poor performer.
In case you think I'm exagerating, check out <A HREF="http://www.anandtech.com/cpu/showdoc.html?i=1927&p=16" target="_new"> this review</A>. try extrapolate and you'll see even a 10 Ghz Celeron would be poor at mostly anything except maybe DivX encoding. Its not even worth overclocking.
= The views stated herein are my personal views, and not necessarily the views of my wife. =