Anybody come across "Portable Apps" (portableapps.com). It seems that you can run these apps from a USB device and they don't leave any trace on the machine. You can run for example Firefox with all your own bookmarks. There are quite a few apps available even now (including a full OpenOffice.org, NVU, Filezilla, Thunderbird, Gaim....), with more on the way - including "operating systems" according to the info on the site. What are the implications for "secure" networks? My nephew apparently uses them all the time at school.