How to create a pseudo-guest account in Lion with FileVault 2? The guest account always had very limited permissions, unfortunately since activating FileVault on Lion it's deactivated by default. (More about it here: Unable to create Guest Account after enabling FileVault.)

Is it possible to give the guest account a password? Or can I create a regular account with the normal guest account's privileges (hence making a pseudo-guest account)?

I simply need FileVault and a limited account for my guest! :)
Guest Account

This account is visible in Directory Utility, but please do not attempt to make it compatible with FileVault 2. Not only for security; there may be other good reasons for Apple making this account not available whilst FileVault 2 is enabled. 

Other accounts

For your guest you might like to create a standard account, or add parental controls. You can probably have an account that is password-free. This is in line with Kyle Cronin's answer to a linked question. 

Recommended reading

Apart from being able to encypt an entire volume, what are the other differences of FileVault 2 over FileVault?