I have been reading for years on my Toshiba Libretto 50
Intel Pentium 75 MHz, 16 MB RAM, 810 MB hard disk, 6.1" TFT display
The great thing about this little notebook is, that you set bios to switch the HD off after 5 minutes of inactivity, then you load the ebook into the reading application (I personally have used Linux and heavily customized Vim editor) and after 5 minutes even the harddisk stops and since this little beauty has no fans or any moving parts you get COMPLETELY silent device. Try this with modern notebooks.
I personally would purchase a second-hand old notebook for reading if I wanted to use LCD screen. I strongly prefer e-ink.
If you want to read everything about ultra portable notebooks, Asus EEE and its numerous wannabe competitors go to the
http://www.liliputing.com/