Yes it's possible.
A few questions.. Do you want to allow them to pay in a different currency than the posted currency?
If payment is in a different currency, how do you want exchange handled?
Are there any taxes on the items? If so, what and how much?
Is there a different tax rate for drinks versus food?
Is there a different tax rate for alcoholic drinks?
Is there a different rate if the bill is over a certain amount?
Do you want to limit how high the bill can get before being presented for payment?
Do you want to retain bills between sessions, in case someone runs a bill and leaves without paying?
Do you want them to be able to carry a bill from one session to the next if they don't have enough money to pay the bill?
Do you want a surcharge for using the !card option?
Do you want to accept only certain cards?
Do you want Paypal as an alternative?
That's all I can think of at the moment, but it'll give you some things to think about that you might not have considered.
