Multiple Android Market Accounts on a Single Device? Is it possible to have multiple Android Market accounts on a Single phone?

If so, how do I do that?

(I have been able to add a second Gmail account, but I couldn't find any option to add a second Android Market account)
Nope, at least not as of now.  You can factory reset your device to remove the first account you set up (on some devices, you can just remove all the accounts without the reset) and then add the other one first, if you would like to use it instead. But if you actively want to use both, you're stuck.