Touchpad Indicator is a very simple indicator created by Lorenzo Carbonell (the Picapy developer), which as the name suggests, is designed to allow you to easily enable / disable your laptop or netbook touchpad.
To install Touchpad Indicator in Ubuntu (10.10 Maverick Meerkat only), you'll have to use the same PPA for Picapy:
sudo add-apt-repository ppa:lorenzo-carbonell/atareao sudo apt-get update sudo apt-get install touchpad-indicator
Once installed, you'll find it under Applications > Accessories > Touchpad Indicator.
See also: automatically disable the touchpad when you start typing (includes a script to enable/disable the touchpad using a hotkey for those with no built-in hotkey for this).
Thanks once again to Lorenzo Carbonell!