PKG files are .tar.gz files. To create them, use Linux (tar czf name.pkg name) or Z7IP (it's a prog). Alot of them are linux scripts. Search for 'linux scripting tutorial' on google. This phone (as well as any other phone on this site) can use C++ apps (they have to be made for each model specifically, they are not universal). That's just the skinny on it. To see the structure of everything, take a couple of PKG's and rename them to name.tar.gz Then you can open it in WinRAR. See what size the icons need to be, the format of the .desktop file, etc. NOTE: Use ultraedit to do this (it's the easiest). NOTE: Each text file needs to be in UNIX format, not DOS. Add me to your MSN, and I'll help w/ that.
I'm so cool, I had the E6 before the E2 launched! Wait. Never mind...