Over at TabletPcReview dot com forum there are folks who have requested the tip, and are requesting more folks do the same. I believe the last I heard was that the tip is in development, and will be available in the next couple of months.
Not sure a link will work, but it's here: http://forum.tabletpcreview.com/ep121-slate/40050-do-you-want-tip-your-energizer-xp18000-your-ep121.html
Has anyone actually gotten an external battery power pack for the Eee Slate EP121 and if so, from where and how is it working for you? I want to order the slate but am concerned about the short battery life.
I ordered a Tekkeon 3450i R2 which has tips made for the asus slat but its 200 bucks but its stackable meaning you can buy extra battery cubes and they hook up on top of each other. See next week how it works.