If you want the best bang for the buck, lighter weight, and maximum battery life using wi-fi (3.5 to 4 hours at least) get a Pentium M processor (Intel Centrino).
If you want a 14.1" or smaller LCD then IBM's are great (as are their keyboards and case construction/durability) as are the Toshiba Techra series, etc.
If you are willing to go up to the 15.4" widescreen (6.2-6.5 pounds for Toshiba M35 series or Compaq X1000/HPZT3000) then these are great notebooks.
You need to specify what the LCD size is that you want. Everything else falls into place after that.
You will get a better deal with exactly the specifications you want ordering online custom.
I am going to college in a few months and am in need of a notebook that will be light enough to carry, but still powerful, and not too costly(meaning under $1600). I've looked at IBM's T series and I loved everything about it except the price. If anyone can help me out in deciding what to purchase it would be greatly appreciated. Thank you.