The techdo.com tech blog website has a portable toolkit available as a 36 Mb zip file download. This is small enough to unzip and fit onto a USB flash drive.
The list of tools is as follows:
7-Zip -- a file archiver (compression) utility for Windows.
Autoruns -- Displays autostart programs in Windows.
Eraser Portable -- secure data removal tool.
Mozilla Firefox®, Portable Edition -- portable version of the web browser
KeePass Portable -- a Password safe.
Notepad++ Portable -- text editor
Process Explorer -- shows system memory usage by processes.
Recuva File Recovery -- restore deleted files
Sumatra PDF Portable -- lightweight PDF reader
Torpark -- anonymous web surfing browser (based on Mozilla Firefox)
This looks like a worthwhile download, especially for KeePass and Torpark.