Provide safety against virus infection on the USB key.
As the USB key with applications moves from PC to PC each PC possibly infected by a virus could contaminate the whole USB key and even possibly the next PC in the chain.
The most risky elements are:
1. The autorun
2. The launcher menu
3. Portable applications
4. Other documents
When dismounting the USB from the menu, or closing the menu, check the aurotun. When starting the autorun, check the CRC of the files. The trick is to check the CRC with an application that should be safe. A simple security working in most cases could be to let autorun start a batch file doing: "copy crc_app.safe crc_app.exe && crc_app.exe". This way even the crc_app.exe got infected it should restore to original on next run. Another way is to check the CRC of that crc_app (which is possibly the launcher menu itself) when closing/dismounting the menu.
It is important to node that it's only an outline of important security improvements, which are mostly based on CRC at dismount compared to the original CRC-32 value. In case of infection it could at least avoid running anything.