Although NetPositive allows you to reject cookies, there are some sites that won’t give you access unless you accept their cookies.
If you allow NetPositive to accept cookies, and delete them later (script follows), then a new cookie will be issued each time, allowing you access, but making the site unable to track you.
Add these lines to the end of ~/config/etc/ppp-script

: ----begin----
if test ${1} = "up"
then
rm -f /boot/home/config/settings/NetPositive/NetCache/Cookies
rm -f /boot/home/config/settings/Opera/cookies.dat
fi
: ----end----

I can’t find any controls in Opera beta 7 to manage cookies, but this tip works for those users too.