I switched from 15" MacBook Pro to 13" MacBook Pro. It is little lighter but the screen is very small. It is good enough for email but not foe anything else. For that I think MacBook Air or even iPad is good enough.
freetinyimages 
さわ 
ロッキーおしょう 
さち 
橋本諭弥 
水琴晶子（みことあきこ） 
Tetsuro Watanabe 
坂本祐央子（さかもとゆみこ） 
神谷保険 
神戸のおいさん 
bokushi