http://www.snapfiles.com/reviews/Back4Win/back4win.html
"Back4Win is an easy to use backup tool that uses zip compression to store all selected files and directories in a single archive. You can adjust the compression level, password protect the archive and more. Backup modes includes a refresh option, overwrite or move (then delete) of files. In addition, you can backup your data as a self-extracting EXE file, label backups with easy-to-find timestamps, span backup sets across disks and more. Back4Win also includes Mozilla Firefox and Thunderbird backup. The program works with any drive letter, including mapped and network drives"
note: this a free version of back4winxp, which is free but not as advanced
Extract with uniextract
Create a file called default.ini
launch back4win
I've tested it a couple times, Couldn't find anything in the registry accept
unfortunetly
HKCU\Sandbox\DefaultBox\Registry\Machine\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\back4win.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.zip\OpenWithList
which probably invalidates portability, because thats all I could find.
It seems to keep the directory structure inside the zip.. which is good though.