2 Organizations and 1 Database

2 Organizations and 1 Database

I own two small companies - unrelated and no cross-over between the two.  One buys and resells houses, the other is trucking technology.  I have 1 employee in each organization.  

Today, everything is in the same DB and separated only by a "Product Interest" field.  However, I need to set up workflows, which will be different in each organization.  I also need to figure out how to set up GMail and integrate it - the email addresses are different as well.  

Any advice on how to separate these two sets of accounts/contacts/leads?  Or, am I better off just doing two databases?  I'd rather do the former and not the latter - if possible.