I have not been into PortableApps.com for long, but I find it highly useful. But there are a few things that have been bothering me. These are not complaints mind you, they are just a few suggestions that came to me.
I think dependencies could start to become a problem. I think, that, just as some help for a few users, we should keep a running list of all the dependencies that each program will need, and also provide a link to the most up-to-date version (or the latest working version for that application). I just think this would help with users who often switch between multiple computers (I think that's actually why you made the applications. xD , that run different OSes (Win9x, NT, etc.).
I also believe it would help users (especially those with rather small drives) save some disk space by UPXing everything possible. All *.dll's and *.exe's are usually shrunken down to 30% their original size using UPX 2.91 (--best --lzma --force --brute --compress-icons=2). I was able to reduce GIMP from 23Mb, to 15Mb. That's 8 Mb (obviously) that we saved. ^_^
I am sure more will come to me, but I have a Psychology test to study for. >.<