Feeds are stored in a database called apprise_1.0.db, your preferences
are stored in a _prefs.obj. The location is different on Windows, Mac,
and Linux.
On Mac, it's: ~/Library/Preferences/com.adobe.apprise.<id>/Local
Store/
On Windows, it's: C:\Documents and Settings\<user name>\Application
Data\com.adobe.apprise.<id>\Local Store\
You could also export and import your feeds in ShareFire, under
Settings -> Import or Export Feeds.
Hope this helps.
-Dan