portableapps.com is great and most of the apps I have come from there...but that's not the only place to get portable apps.
Wikipedia has a very complete list of portable applications. There are a few portable flavors of TOR but the one I use is TORPark. I'm not sure if it's supported anymore but my copy still works for me. It's the only one I know of that's pre packaged with a browser and ready to go without building or compiling. The only drawback is that you can't use regular portable firefox and TORPark at the same time...the computer gets confused.

I've heard that there's an Opera based version (OperaTOR?) if that's more your cup of tea.