If you are using mobiles of these companies and are not using their PC suites. You are missing a lot.
Both these companies offer nice programs to sync your contacts, music, pictures and videos. They also allow you to convert the videos so they can be played on your mobile.
Nokia PC suite
I like the nokia PC suite because it detects the phone automatically and also display the picture of the phone. So you can be sure it has detected your particular phone. It pops the nokia PC suite in a small window with all the shortcuts.
Once you click a particular shortcut a window opens up with the app.
Like address book which will let you import contacts or back them up etc.
Similar all the multimedia have programs where you can import, edit and convert them.