I'll start with a sad announcement made by Google
Although Google released Picasa 3.0 for Linux, a company spokesperson said that version 3.5 is only being released for Mac and Windows due to low adoption of Picasa 3.0 among Linux users.
It's kind of sad, because as much I enjoy the Linux's software variety, Picasa is irreplaceable from my point of view. The latest version ported to Linux is 3.0, and.. the latest Windows version is 3.6 which have cool features like face recognition and lots of bugs fixed. I really don't understand why is so hard to maintain the Linux version because even the version installed from Google's repository is emulated with Wine (and probably a little bit changed, but.. the hard work is done by Wine). Anyway, here's how you can have Picasa 3.6 (or the latest) in Ubuntu.
You can skip the first step if you have it installed on a Windows partition,or you can get the installation folder from another PC.