You can clear the browser cache simply in the browser options.
If I were you , I would follow John Clark's memory optimization post in the General Section of this forum (Sticky Notes)
http://www.blackberryforums.com/gene...ee-memory.html
and reload the OS, or the latest OS for the 8707.
http://www.blackberryforums.com/gene...-119-cdma.html
do a complete backup first. (although the upgrade will do so also).