Personally I hate Adobe AIR but it would be a great thing to make portable (however messy flash runtimes can be).
Program: Adobe AIR
License: Freeware
Description: Some kind of runtime that's supposed to let you run apps on more than one platform, like Java.
Website: http://www.adobe.com/products/air/
Does the presentation running mean I have Adobe AIR?
If so, it's already done. It can't be legally redistributed, though.
Install Firefox, then install Adobe AIR (e.g. on your own computer). Find your Firefox profile directory. Oh, while you're at it, install the latest Flash if you don't have Flash portable. Anyway, copy everything in the local plugins folder to the one in FirefoxPortable\data. Adobe AIR to go.
You could probably download 'Adobe AIR.dll' somewhere and just put it there, but doing so would be illegal (a violation of the EULA). There are so many sites that host various .DLLs, and they're a godsend for those who screw up an installation of something, and Windows complains it can't find a .DLL with no advice as to how to fix it.
Air is not even close to a browser Add-on really. Adobe AIR is like a local runtime such as java. Adobe AIR is for running apps, look up DestroyTwitter, and there are LOT of other Twitter apps that run in Adobe AIR.
Right from the site...
"For developers
The Adobe® AIR® runtime lets developers use proven web technologies to build rich Internet applications that run outside the browser on multiple operating systems."