If your a fan of running an application completely on your USB drive, check out the new PortableApps Suite. It’s really great. I’ve been using PortableApps for a while, and this is a real nice suite. Now things are easier to access than ever. The next improvement I’d like to see is some Mac versions become available. The ultimate solution would be Mac/Win/Linux versions that use the same data directory. At that point it would truly be portable. It’s also cool enough to work with third party applications, so you can add other things not available through them to the suite such as everyone’s favorite Putty. Great for Firefox on the go.
The advantage of the suite is not only the easy install, but the ability to quickly open applications without navigating to them. There are other tools out there like PStart, but this is in my opinion a little more polished.