Not necessarily, when comparing apples to apples. The P4 3.06GHz processor isn't necessarily any faster than it's P4-M counterpart. The only differences lie in the details. The P4-M's have built in power management features that the desktop chips may not have, and they usually run at lower voltages to keep power draw as minimum as possible. Mobile chips usually cost more to produce, however, and they pass the savings along to the customer (meaning Desktop CPU notebooks generally cost less than Mobile CPU ones). But, Intel's newest notebook creation is the Pentium-M class of chips, which run at a current top-speed of 1.70GHz (courtesy of Dell's line-up of notebooks). I have no experience with these particular chips, and I can't say how they fit in in respect to performance versus the P4 and P4-M chips, but maybe someone else can point you to some reviews.
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