Rated 5 out of 5 stars
> Thanks to the video tutorial below this is working in Firefox 8, Linux. Basic info: download the XPI file (right-click install button), extract, open install.rdf in a text editor and change em:maxVersion to 8.0.*
Or disable Add-on compatibility checking and in the extensions manager click Screegrab's Compatibility button and select 'This add-on still works'.
Save Complete and Save Visible portion both work fine for me in FF 8.