Cooling fan questions

[Joseph Fisher]

Forgive me if this has been dealt with prior (if so could someone point 
me to the thread)

I have a 15" DVI TiBook 800MhZ - 1Gb RAM - 60Gb HD - I've owned about a 
year and a half.
Recently I've noticed that the cooling fan is running more frequently 
(almost constantly).

As I am writing this I have iTunes playing a net radio site and I have 
Apple mail running via ethernet port. Other than background processing 
of the OS that's all that is up, loaded, and running and yet the 
cooling fan is plugging right along without stop.

I use my TiBook either on my lap at home or with a Targus podium 
coolpad at the office, but I don't sense a change in the amount of time 
the fan is running at either location.

I hadn't noticed the fan running quite as often before and the pgms and 
my usage has not changed. The biggest factor that I can think of is my 
upgrade to Panther.

1) Is Panther that much more CPU hungry?  I used Jaguar prior and 
didn't have this much fan activity.

2) Has anyone else experienced this with their TiBook?

3)  Also, in others experience which programs or types of pgms, tend to 
tax the CPU more and cause the heat and the fan to operate more?

Thanks for the input
Joe F.