CPU Upgrade Advice?

[verdan]

My laptop is quite a pretty beast, but It has 3 big problems. It gets hot, its fans run a lot, and its battery life is less than stellar. I did some browsing online and found a fascinating site, it talked about upgrading the clawhammer AMD athlon 64 3700+ to a Turion ML-44. This is much lower watt, it is much cooler and so the fans run less, and it has a better battery life. The laptop is out of warranty so that's not a concern. I've built desktop computers before, and messed with processors. The only real problem is that on the comments it looks like a decent percent of the people who tried to upgrade couldn't get it to work. The processor is also fairly expensive. I can get it from Excaliber for about $300. If you return it in 14 days they will charge 15% restocking, so that's $45. I'm a poor wolf, but my dad gave me some money for a graduation gift and this seems like a good choice. I was also wondering... someone mentioned that they could put the processor from their laptop in a desktop. Is that actually possible? I have a desktop with an athlon64 3200+, so the 3700+ would be an upgrade there as well, if it works. So... I know some of my friends are computer experts! Any advice? The forum is at http://www.notebookforums.com/thread140189.html
I would REALLY appreciate any input you guys could give...