Is this possible?
I currently have my iPhone registered for the developer account at my company, and was wondering if I could start my own account and register my phone with that one, too, so I can test my own applications.
Any information would be greatly appreciated. I couldn't find anything on Developer.Apple.com
Yup, it's just another provisioning profile that you install on your phone.
Yep, nothing to worry about. I have 3 different developer accounts with certificates (both dev and ad hoc) on my phones and not a problem.
Your iPhone is not "registered for the developer account"; instead, you have a membership in the Developer Program which permits you to create Provisioning Profiles.
A Provisioning Profile contains a list of device identifiers (UDIDs) and allows applications you create to run on those devices only.
A single device can be listed in any number of Provisioning Profiles. However, Apple limits the number of devices a program member may generate profiles for, so that you don't start circumventing the App Store.
In other words, your iPhone is not tied to your developer account. Rather, the apps you create are tied to your iPhone. Your iPhone can run apps from as many developer accounts as it has room to install them.