Hi Eric -
There is not a direct way to transfer ownership, but here are two workarounds:
1. Export the employee's entire account and then import the backup file into your account.
Note, this will import ALL of their tasks. So if there are queues you do not need you can delete the copies in your account after importing.
2. You can publish the queue from the employee's account:
Then from the published queue, click the "Copy to GQueues Account" and a copy will be created in your account.
Once transferred using either way above, then you can delete the original in the departing employee's account.
-Cameron