I've just completed making photoshop 7 (the best tradeoff between speed and features imo) portable, using a loader with NSIS in a similar fashion to most of the apps on this site. I know it's not open source or freeware, but it is simple enough to UPX-pack the main files and drop them into the directory, and you can delete a LOT of the unneeded plugins and resources (textures and so on) and it squeezes down into around 25-30mb, maybe less if you are hardcore about it.
I was just wondering if there was interest for this kind of thing, and whether it violates portableapps ethics somehow to post the loader here, since the app it targets is not open source... I wouldn't post copywrited files or anything, just the loader.
I know photoshop isn't really something you'd carry around with you all the time, but there's a better reason (in my daily use) for using portable apps, and that is to 'set and forget'... it's great to add plugins, brushes, textures, workspaces, etc. to my photoshop setup, and know that I can just add it to my backup list I do fortnightly, and know I'll NEVER have to set up photoshop again. This is also useful for my email and chat, etc. Just saying there's more than one reason to use portable apps, even if it's not for the portability.
I should also mention that I could pretty much make loaders for any large apps, and was thinking about doing dreamweaver next, but I thought I'd check interest first.