How can I tell if my employer is GPSing my location on my Blackberry Bold?

Taking out the battery isn’t even a way to be certain these days. Built-in, non-removable batteries can keep the device operational for tracking purposes (and even voice recording purposes). Of course that all depends on the device itself.

I assume you work for some type of delivery company?

Go to page 193 of the user’s manual:

Test to see if you can get your GPS location
Depending on your wireless service provider and wireless network, this feature might not be supported. To perform this task, you must pair
your BlackBerry® device with a Bluetooth® enabled GPS receiver if your device does not have an internal GPS receiver.
1. On the Home screen, click the Options icon.
2. Click Advanced Options.
3. Click GPS.
4. Press the Menu key.
5. Click Refresh GPS.
The longitude and latitude coordinates for your current location appear.

Turn off location aiding:
Depending on your wireless service provider and wireless network, this feature might not be supported. By default, location aiding is turned
on to improve the performance of GPS technology. When location aiding is turned on, your BlackBerry® device connects to a central server
periodically, which can increase your data service charges. To avoid these charges, you can turn off location aiding, but it might take longer
for your device to get your GPS location. For more information, contact your wireless service provider.
1. On the Home screen, click the Options icon.
2. Click Advanced Options.
3. Click GPS.
4. Perform one of the following actions:
• To turn off location aiding, change the Location Aiding field to Disabled.
• To turn off location aiding when roaming, change the Location Aiding field to Disabled While Roaming.
5. Press the Menu key.
6. Click Save.