I think it's worth mentioning that Config Editor comes in package called gconf-editor, installable through Application manager.

You can also set the update interval with gconftool-2 (which is part of gconf2 and always installed on Maemo 4) on command line as shown below. Replace X with number of minutes, e.g. 10080 for one week. No root access is required.

gconftool-2 --set /apps/hildon/update-notifier/check_interval --type int X