If you need a "desktop" computer that's also portable, go for a laptop, but for most people a netbook will suffice. Netbooks are smaller, great for on the road emails, social networking, and light to moderate processing duties.. My netbook runs Windows XP Home, has 1.5gb or RAM, and a 160gb internal hard drive. I love it!
And now we have 7" "netbooks" on eBay running Windows CE that are selling for as cheaply as $49 -
A 7 inch smartbook running WinCe 5 and using a Anyka Arm 9 CPU, lyrics player, video, electioreader software ,PDF etc.