Just an update for those who like the Turbo feature (a necessity here in rural cyber-bog)
Google Gears is finally (mostly) playing nice with Firefox 3.5
You can download at http://gears.google.com though some warnings:
1) There download appears to be rolling in and out of commission.
2) Conflicting reports about whether the release for Linux or OSX versions of FF3.5 is available.
If you manage to get it, it seems to be working for me.