Fiddler, the HTTP debugging proxy is an excellent tool. I use it almost every day for AJAX development, server debugging, and examining almost anything else that flys through tcp/80 on which I need to keep an eye.
I'm a huge fan of portable apps. In fact, the fifty or so portable apps that I use regularly follow me from computer-to-computer thanks to Dropbox. I was just thinking how great it would be if Fiddler was portable. I checked the download page but was disappointed to see a portable version wasn't offered. Then I wonderedâ€¦
I downloaded Fiddler4 and used 7-Zip to open
Fiddler4BetaSetup.exe. I wasn't surprised that I could open it; after all, many installers are self-extracting .exe's. What did surpise me is that when I unzipped the whole lot to its own directory, it ran perfectly. I haven't testing it thoroughly to see if anything is broken, but it did the job and I'll certainly be adding it to my portable toolkit.