I've seen a few Roundcube Tango sets (here and elsewhere) and while they are a good start, they either deviate too far from the Tango icon philosophy or are lacking certain icons and/or have outdated icons. Thus, I put together a new set of Tango Icons.
Please note that they are ALL Tango icons. I've seen complaints that Tango icons don't look like or match the metaphors of the original Roundcube set, this is intentional. The Tango set is about trying to unify looks across platforms, programs, and web tools. It may be disjointing for existing users to switch metaphors, but for new users the metaphors are easily understood. Of course, your mileage may vary.
Anyway, enjoy.
(http://img341.imageshack.us/img341/5707/realtangodemole3.png)