I have one. It's an [link|http://au.lge.com/md/product/prodcategorylist.do?actType=detail&currPage=1&categoryId=0200000302&parentCategoryId=0200000003&categoryLevel=3&productId=1100000799|LG DP9911P] and can play DVD-RWs made on our Toshiba DVD recorder more-or-less okay (it gets slighly out of sync from time to time and then suddenly races to catch up - I think it's the encoding mode at fault). It has a 7" 16:9 screen and a full battery lasts about 4 hours. LG have a slightly more expensive model that can also play DivX encoded content.

My wife found it for me at Christmas because the older one I had had for 3 or 4 years (chinese thing rebadged by Voxson) couldn't play DVD-RWs and it had a failing lidswitch. Basically, I wore it out, which I still think is kinda unusual for a portable DVD player, but there you are. It spent quite a few months with me on the morning and evening train trips.

There used to be a number of Panasonic, Sony etc models, but the market here seems to have been swamped by a-bit-too-cheap weird-brand asian imports that even the retailers don't like selling. So be choosy. You may have to visit quite a number of electronics stores.

Other sampling:
[link|http://www.sonystyle.com/is-bin/INTERSHOP.enfinity/eCS/Store/en/-/USD/SY_DisplayProductInformation-Start?CategoryName=hav_DVD_DVDPortables&ProductSKU=DVPFX705&INT=sstyle-hav_DVD-catpfeature-DVPFX705|Sony DVP-FX705]
[link|http://www.tacp.toshiba.com/dvd/portable.asp|Toshiba have several]

Wade.