Use Google Talk with multiple accounts

(Motorola Droid, Android 2.2.2) My new employer uses Google Apps to manage e-mail etc. They're also big into instant messaging for intra-company communication. On my device I have my personal account and have added my company account so I can use Gmail for either, have consolidated calendar, etc. However, the Google Talk app is tied to my main (personal) Google account. I can't see a way to get it to use the company account or, better, allow both accounts to be active. How can I use Google Talk with a secondary account?