I've installed Picasa 3.9 via the instructions at webupd8, however the login window keeps failing with the message, "You must be connected to the Internet to use this feature." If "Try again" is tried I'll successfully pass the first login screen of username and password. Next I'm prompted for the verification code which then takes me back to the "You must be connected to the Internet to use this feature" screen again.
I wonder if you'll be better off creating an application-specific password, which you can do from within the account settings section of your Google profile.
install iexplorer first:
you can login to picasa web albums and post photos to Google Plus.
I tried a number of different tutorials trying to get Picasa 3.9 running under Wine on 12.04 64-bit. They all left me with a broken login screen, even after installing IE6 using Winetricks.
After reading the above comment referencing IE7, I ran
winetricks ie7, opened IEe7 and tested logging into picasaweb.google.com. Though somewhat buggy, I authenticated properly. Sure enough, Picasa 3 allowed me to authenticate as well, though when checking "trust this computer", a pop-up displayed (also blank, like the previously broken login window when using IE6).
After dismissing the popup and closing the "Processing" window I was able to hit the "Share" button and was presented with a somewhat familiar Google+ share dialogue.
Thanks to Tomasz for leading me in the right direction.