Use a filemanager that lets you access those areas or with xterminal use copy eg:

First list the .deb to find out its name:

Depending on where you got it, the location might change:

Ovi Store paid debs: /var/tmp
Other debs: /home/user/MyDocs/.apt-archive-cache
Debs installed through apt-get: /var/cache/apt/archives

Credits to MohammedAG:http://talk.maemo.org/showpost.php?p...8&postcount=10

The output would provide eg: Zenbound1.2.deb

Then copy it to wherever you want (this case the root folder in the default file manager)

This is important. I do not know at what point the Application Managers cleans the cache, so it is recommended that you do this during the installation.

To overcome the cache problem you can change this file:
Change the value of "clean-after-install" from '1' to '0'.