Web downloads vs Add/Remove downloads

After downloading Skype and Picasa from their web sites, I can find the programs in My Downloads and they have an RPM extension. When I add software by using the Add/Remove function, the only way I can find them, besides their listing on the desktop menu, is to go back to the Add/Remove function then do a search of installed packages. All the posts I've read concerning the remove function of Add/Remove mention that many times it doesn't clear all the files related to the package, and apparently there's no way to get to those files, as you can in Windows and delete them manually. Does the same problem occur when you delete RPM downloaded software? Also wondering why Skype was listed in the desktop menu after installation, but Picasa wasn't, and I have to go to terminal and type in /usr/bin/picasa to open it.

 

When you remove programs through the package manager (e.g. Add/Remove programs) it should remove all files, with a possible exception of the config files (I haven't looked into that), but config files take up very little space anyway. However, the package manager does download packages into a cache directory before installing and these files are left there even when you uninstall a program, it is possible to disable this behavior by the command "sudo sed -i.1 3s:1:0: /etc/yum.conf" taken from here, with a side effect being that you will have to redownload packages should you need to reinstall them or if an install fails for whatever reason. I just empty the cache folders manually every now and then (usually when I do a backup) with the command "sudo rm /var/cache/yum/*/packages/*" there is a way to do that through yum, but it is quicker just deleting them. When you delete rpm downloaded software there should not be a package file stored in the cache, but there will of course be the file you downloaded.

An application should automatically show up in the menu if it has a correctly written .desktop file which are normally stored in /usr/share/applications, my guess is the Picassa didn't provide this file in their package and Skype did.