Shoutbox

Get the Pentium M (aka Centrino) but avoid the Celeron M if you can as like the desktop part, it's nothing special.

Pentium M has 1MB or 2MB L2 Cache
Clock Speed 1.50 to 2.26 GHz

Celeron M has 512k or 1MB L2 Cache
Clock Speed 1.20 to 1.60 GHz

The large cache allows a significant reduction in memory data latency providing a big performance improvement.  So therefore the Pentium M (not the Pentium 4-M) will provide the better performance.