Yes.
With a judicious use of silly-putty or play-dough both a P4 and an Athlon can be fitted onto any mobo.
Of course if you want them to actually do something other than sit there and look pretty, well that's a whole different kettle of fish-sticks.
If you want the processor to actually work, than an Athlon is way out and a P4 is only possible <i>if</i> it was a P4 Celeron to begin with, which it probably wasn't. But who knows.
If you could tell us the actual motherboard involved it would make a huge difference to the quality of information. Even just the socket type would be ten times more useful than the extremely limited information that you've given.
"<i>Yeah, if you treat them like equals, it'll only encourage them to think they <b>ARE</b> your equals.</i>" - Thief from <A HREF="http://www.nuklearpower.com/daily.php?date=030603" target="_new">8-Bit Theater</A>