I have a wireless G notebook, a desktop with wireless G built in, and a PS3.  I'm hoping to move my current G router to another location in the house I'm currently in (very very very old and large plantation home).  I has very thick walls and over 100 feet from one side to the other.  I'm thinking I need to get a stronger router to improve upon the range of my current one.  Will a wireless N router improve the effective range of wireless G components, or will I need to get wireless N adapters for them as well?
 
Thanks for any help you might have.

Oh, and I was thinking about getting the DIR-655, unless something else would suit my needs better.

I think you need N on both ends since N works at 5 GHz and not 2.4 GHz like G. Why don't you get a Range Extender or load DD-WRT firmware (if your router supports it) which allows you to boost the power?
 
Grumpy

Someone correct me if I'm wrong, but you may be able to pick up another router and simply use it for an access point which should extend your range also.