The Regional Support Centre Scotland North and East have produced a form of portable assistive technology suite. (See my blog entry for 28 Oct 2008.) Their version has broken down into three sections - AccessApps, LearnApps and TeachApps.
The full list of sections covered includes
Planning and Organisation
Reading and Writing Support
Simulation and Modelling
All this software will operate on a USB memory stick and therefore can be carried anywhere and used on any (Windows) computer. This is an excellent extension of the PortableApps suite. Note that the full collection is more than 6GB.