I try not to deal in debt in the real world, why would I deal in debt on the internet?? Stick to Bitcoin, its a better idea.
Unless you only ever use cash and bitcoins, you do deal in debt.
Do you deposit money in a bank account? That is accepting Bank IOUs for your cash. Do you ever give somebody a check? That is giving that person an IOU. Later they give it to their bank and that bank gives it to your bank, and then your IOU is used to cancel some of the bank IOUs. Ripple just makes these relationships more explicit and open, not everything has to go through the central bank anymore.