Best practices for updating two list from different site collections on MOSS using a Blackpearl workflow

Hello,

   In a MOSS 2007 portal, we want to update a list on one site collection when a list in another site collection is changed (automatically by using a Blackpearl workflow)

Questions: Is there a best practice to do that? What's the best way to do it?

Any help will be appreciated.

Thanks in advance

- Guillermo - Digital Dimension.