This should register Picasa with Firefox 3. You need to have Gnome
installed for this to work - this is a limitation with Firefox.
download
http://leiz.org/picasa/picasa.schemas
sha1sum: 3d06788d09acc4e829f7cf6000525440f2d4de43
Make sure your system has the latest updates. This probably won't work
if you have a fresh install with Firefox 3.0b5.
On Ubuntu 8.04 Hardy, as root:
mv picasa.schemas /usr/share/gconf/schemas/picasa.schemas
gconf-schemas --register picasa.schemas
On Fedora 9, as root:
mv picasa.schemas /etc/gconf/schemas/picasa.schemas
export GCONF_CONFIG_SOURCE=`gconftool-2 --get-default-source`
gconftool-2 --makefile-install-rule /etc/gconf/schemas/picasa.schemas
I think it should work right away, but if not, try logging out and
back in.