I'm a newbie to Linux and Maemo. Please correct me if I'm wrong.

Everyone knows that installing apps from repository is official.
However, the question about installing app outside repository is a worthy question. And they want the answer for that question, not the suggestion that installs apps from repos. For example:

1) User doesn't have wifi. He can copy apps which his friends downloaded and installs to his phone.

2) Waiting to download 1000mb apps with slow internet is horrible. Even more terrible with the phone. Many people may want to install many apps at the same times (they don't care about update) instead of clicking 100 times and waiting many hours to download and install apps.

3) I tried to backup the phone, and it only backed up the setting, calendar, ... but not all apps. If we flash firmware, we have to re-install apps, but nobody wants to download and install a ton of apps. It's easier if they already have the apps and they can install locally via pc but Nokia may not support that.

I think Nokia should support downloading apps via pc and allow install to the phone later like iTune and iPhone. It's much easier for user.