Someone has posted a precompiled version of the new version of Google Gears for 64 bit Ubuntu distros! (yay thanks, this is too much work to do all the time so I almost never end up updating)

Just save the file, then in Firefox do file> open file > *filename* and install the extension. If you already have it installed, it will update the old version (don’t worry about removing the old version first. )

http://nielspeen.com/blog/2009/02/google-gears-64-bit/

–aliencam