Hi Ihotka,
I put a little service called Spootnik (
http://www.spootnik.net) together which synchronizes Basecamp directly with OmniFocus and vice versa.
Basecamp supports to-do responsibilities and sends an email if the responsible party changes. Spootnik synchronizes those responsible parties as Context into your OmniFocus database.
Thus changing a responsibility of a task (inside Basecamp) means to change the Context inside OmniFocus (e.g. "Phone" to "Phil" or "Phil" to "Veronica") and let Spootnik do the synchronization work. Have a look here:
http://www.spootnik.net/faq.html#res...ity_as_context ...
Best regards,
Lars