Roll your own portable application of potentially any program with AppCompactor. This portable power user's delight crushes program files, often shaving 50 percent off the size on disk.
AppCompactor melds 7-Zip and UPX to compress and archive DLLs, EXEs, JARs, and other files essential for running any program into a package that doesn't need to be unarchived to run. Programs that have been compacted run smoothly from a flash drive or other on-the-go storage devices. When you run AppCompactor, it will ask you to point it at a program directory. From there, you can choose the type of compression you want to run. NRV2E is the default setting, with other choices including NRV2D, LZMA, BRUTE, and a decompress option. You can also opt out of compressing JAR and ZIP files, although the default is to compress them down. As the application runs, it opens a DOS window that shows you the progress of the compression cycle. This should help observant users with fast eyes to keep track of any errors that occur.
Saving the compressed program output to the hard drive and then copying to a USB key gave faster results than outputting directly to the flash drive. However, this is not a program to treat cavalierly. When using it, it's essential to read through the instructions. Choosing to compact the main program executable can result in rendering the compacted program inoperable. In other words, do not compact C:\Program Files\Firefox\Firefox.exe, for example. C:\Program Files\Firefox\Files would be fine, though.