I am a fan of the portableapps system and have been for several years. I have begun to mess around with web development, adobe air, and android development. I have several portable apps that I use for this.
1) Eclipse Portable - Java, Adobe Air, HTML IDE. Not the latest version but certainly adequate for some of the development I am doing.
2) Mozilla Firefox Portable - This is the browser that I use to preview HTML coding.
3) Inkscape Portable - Open source SVG graphics editor. Useful for logos.
4) IcoFX Portable - an icon creation/editing tool.
5) ColorPic - Get the color codes for any pixel on your screen.
6) FotoGrafix Portable - an image editor. Useful for combing images, resizing images, and touchups.
I find these apps quite helpful in my daily development work.