Just to say that we would definitely like to see this too. Almost every time I add a new customer I forget to change it from the contact name to the business address. Then when i create a new invoice, the company name is not shown in the 'customer' drop down, and it is not possible to search for the company name here either. It's really daft behaviour, and the obvious default should be to the company name. Please look into fixing this ASAP.