Try syncing your business gmail account to your phone by following these steps below. After this is done you should then have the option to pick which account you would like to use.
Google data synchronization
Find it: Menu > Settings > Accounts & sync
-The Google apps on your phone give you access to the
same personal information (emails, events, and
contacts) that you have on a computer using Gmail,
Calendar, and Contacts. It’s easy to synchronize the
Google apps information you want to keep up to date.
Select apps to synchronize
1 Touch Background data.
Tip: To save battery power do not touch Background
2 Touch Add account to add the apps you want to
synchronize, like Google, Facebook, or Corporate.
This information and more can be found by following this link to the Motorola Droid user manual: http://infomanagerdoc.ddc.vzwcorp.com/EQUIPMENT_GUIDE/equipment_guide/WEP/Manual/Motorola/droid.pdf