FAMFAMFAM flag icons by Mark James.
To get started, checkout http://tkrotoff.github.com/famfamfam_flags/
If you are using Ruby on Rails, check https://github.com/tkrotoff/famfamfam_flags_rails
rm bl.png bv.png famfamfam-flags.png gf.png hm.png mf.png re.png sj.png um.png
glue . . --sprite-namespace= --namespace=famfamfam-flag --each-template="%(class_name)s { background-position: %(x)s %(y)s; width: %(width)s; height: %(height)s; }\n"
As stated on http://famfamfam.com/lab/icons/flags/: "These flag icons are available for free use for any purpose with no requirement for attribution."