Development
Dreamweaver - Can be made portable using a launcher (Script Here)
NSIS Portable - Portable version of NullSoft Scriptable Install System
Nvu Portable / KompoZer Portable - Portable webpage/website editor
WOS Portable - A portable apache webserver with php and mysql (I found WOS to be the easiest to set up)
XAMPP - A portable apache webserver with php and mysql
Uniform Server - A portable apache webserver with php and mysql