As reported above I use a Sony PRS-600 with an additional after market 14gig slot in memory card
Had it for a year and can report it is one of the best, if not the best, "gadget" Ive ever bought. I now have over 900 books stored on it, categorised and indexed into collections such as "history" or by author.
Extremely simple to use, with scalable font sizes so you can make the print bigger. Also stores wav and other audio files such as MP3s - so I have a stack of audio books on there too and radio plays like the classic BBC Hobbit and LOTR series. I use it for about an hour a day or so, and it requires charging once a week or so (music and audio sucks up the power much quicker - about 4 hrs playtime from one charge). Same size as a standard softback novel, and wieghs about the same so its cool brushed alloy cover feels good in the hand. Works on either touchscreen or a set of very simple bottons below the screen. Onboard dictionary function, and you can use it to make handwriting notes, store pictures and a few other basic functions.
The Sony has a distinct advantage over other readers in that it is multi platform so reads many more file formats than its competitors like Kindle. Its also a lot classier as its metallic alloy covered rather than cheap plastic, so a lot more robust. I like its clean minimalistic look - I think the others with keypads look cluttered, and a colour screen is a waste of time IMHO as ebooks are black n white.
When I was buying one I went into Barnes and Noble to do a prouct comparison with the Kindle and Nook....even their own B&N staff said the Sonly ones were much better at what they did. Unlike Kindle the Sony has no issues with copyright covered material from iffy sources like EBook30.com and Sony do not pull stupid tricks like auto deleting any dodgy material when you log onto their sites (which Kindle do). Its clean and simple...it reads books, stores picures and notes, and plays music. If you want other functions Id suggest you are better getting a small format PC Tablet like the Acer ones. Kindle seems to be a lot less user friendly and a lot more cluttered. The NOOk is just less value for money as it suffers like Kindle from a much more limited file format range.
The only downer, and its the same for all the ebook readers, is that the screen is NOT backlit, so you need to be in a light environment to read such as a bedside lamp. Sony do an aftermarket cover with a built in AAA battery powered reading light for when you are on the move.
Possibly the best £200 Ive ever spent.
Now for the bad news. Sony have no plans to release it in Thailand as they do not see a market for them here. You can get them in Singapore though. Caveat Emptor though.... they are being counterfeited by Chinese companies so make sure you buy from a reliable shop or net site.
Hope that is helpfull.

"Science flew men to the moon. Religion flew men into buildings."
"To sin by silence makes cowards of men."